Abstract
The invention relates to an apparatus (10) and a method for optically characterizing or processing an object (60), and to an object transport unit (55). The apparatus (10) comprises an object carrier (50) for receiving an object (60); an optical characterization or processing unit (15), comprising at least one device for producing or for receiving light (140) and an objective (40) for exposing the object (60) using the light (140) or for capturing the light (140) from the object (60), wherein the objective (40) has an end face (46) facing the object carrier (50), wherein the end face (46) has an edge (47), wherein the objective (40) further defines an optical axis (502); at least one membrane (100) introduced between the objective (40) and the object carrier (50), wherein the membrane (100) has a portion (120) configured for penetration by the light (140), wherein at least the portion (120) of the membrane (100) is movable in the axial direction with respect to the optical axis (502), at least one membrane holder (80) for holding the at least one membrane (100), and at least one immersion medium (160) which is at least introduced between the membrane (100) and the object carrier (50),
wherein the membrane (100) and the membrane holder (80) are fastened at a point outside of the objective, and wherein the membrane (100) is arranged at the membrane holder (80) in a manner that first contact points (81) between the membrane (100) and the membrane holder (80) are located on or outside a lateral surface (510) which is formed by a geometric extrusion of the edge (47) of the objective (40) parallel to the optical axis (502).
The apparatus (10), the method and the object transport unit (55) facilitate the optical characterization or processing of an object (60) in a manner that meets the specific needs of high-throughput industrial applications.
Claims
1. An apparatus (10) for optically characterizing or processing an object (60), comprising an object carrier (50) for receiving an object (60); an optical characterization or processing unit (15), comprising at least one device for producing or for receiving light (140) and an objective (40) for exposing the object (60) using the light (140) or for capturing the light (140) from the object (60), wherein the objective (40) has an end face (46) facing the object carrier (50), wherein the end face (46) has an edge (47), wherein the objective (40) further defines an optical axis (502); at least one membrane (100) introduced between the objective (40) and the object carrier (50), wherein the membrane (100) has a portion (120) configured for penetration by the light (140), wherein at least the portion (120) of the membrane (100) is movable in the axial direction with respect to the optical axis (502), at least one membrane holder (80) for holding the at least one membrane (100), and at least one immersion medium (160) which is at least introduced between the membrane (100) and the object carrier (50), characterized in that the membrane (100) and the membrane holder (80) are fastened at a point outside of the objective, and that the membrane (100) is arranged at the membrane holder (80) in a manner that first contact points (81) between the membrane (100) and the membrane holder (80) are located on or outside a lateral surface (510) which is formed by a geometric extrusion of the edge (47) of the objective (40) parallel to the optical axis (502).
2. The apparatus (10) according to the preceding claim, wherein the membrane holder (80) is connected to an objective stage (20) that is formed to receive the objective (40).
3. The apparatus (10) according to any one of the preceding claims, wherein the membrane holder (80) is connected to an object stage (51) that is formed to receive the object carrier (50).
4. The apparatus (10) according to any one of the preceding claims, wherein the membrane holder (80) is connected to the object carrier (50).
5. The apparatus (10) according to any one of the preceding claims, wherein the membrane holder (80) is connected to a further part (16, 17) of the optical characterization or processing unit (15).
6. The apparatus (10) according to any one of the preceding claims, wherein the objective (40) has such an exchangeable setup that the objective (40) is able to be exchanged while the membrane holder (80) and the membrane (100) remain at the apparatus (10).
7. The apparatus (10) according to any one of the preceding claims, further comprising at least one positioning element (90, 91), wherein the positioning element (90, 91) is configured to move the membrane (100) in the axial direction with respect to the optical axis (502).
8. The apparatus according to the preceding claim, wherein the positioning element (90, 91) is arranged in a manner that second contact points (96) between the membrane (100) and the positioning element (90, 91) are located on or outside of the lateral surface (510) which is formed by the geometric extrusion of the edge (47) of the objective (40).
9. The apparatus (10) according to either of the two preceding claims, wherein the membrane holder (80) or a part of the objective (40) is simultaneously embodied as the positioning element (90, 91).
10. The apparatus (10) according to any one of the three preceding claims, wherein the positioning element (90, 91) is connected to the objective stage (20).
11. The apparatus (10) according to any one of the four preceding claims, wherein the positioning element (90, 91) is connected to the object stage (51).
12. The apparatus (10) according to any one of the five preceding claims, wherein the positioning element (90, 91) is connected to the object carrier (50).
13. The apparatus (10) according to any one of the six preceding claims, wherein the positioning element (90, 91) is connected to the further part (16, 17) of the optical characterization or processing unit (15).
14. The apparatus (10) according to any one of the seven preceding claims, wherein the membrane holder (80) and/or the positioning element (90, 91) comprises fastening elements (185) which are configured to move the membrane (100) in the lateral direction between the objective (40) and the object (60) by way of rollers and/or sliding surfaces (85).
15. The apparatus (10) according to any one of the preceding claims, wherein the membrane (100) or the membrane holder (105) is elastically or plastically deformable in a manner that the portion (120) of the membrane (100) is movable in the axial direction as a result thereof.
16. The apparatus (10) according to any one of the preceding claims, wherein a working distance d of no more than 5 mm is configured between the end face (46) of the objective (40) and a surface of the object (60).
17. The apparatus (10) according to any one of the preceding claims, wherein the immersion medium (160) comprises a photosensitive material.
18. The apparatus (10) according to any one of the preceding claims, wherein the membrane (100) separates the immersion medium (160) and a further immersion medium (170) from one another.
19. The apparatus (10) according to the preceding claim, wherein the further immersion medium (170) has been introduced between the membrane (100) and the objective (40).
20. The apparatus (10) according to either of the two preceding claims, wherein a refractive index of the further immersion medium (170) differs from the refractive index of the immersion medium (160).
21. The apparatus (10) according to any one of the three preceding claims, wherein a viscosity of the further immersion medium (170) differs from the viscosity of the immersion medium (160).
22. The apparatus (10) according to any one of the four preceding claims, wherein at least one of the immersion media (160, 170, 175) is a liquid photoresist.
23. The apparatus (10) according to any one of the preceding claims, wherein at least the object carrier (50), the membrane holder (80), and the membrane (100) are present in the form of an object transport unit (55), which is at least transferable between a handling unit (200) for immersion media and a lithography unit (220), wherein the handling unit (200) is at least configured to apply the immersion medium (160) used between the membrane (100) and the object (60), and wherein the lithography unit (220) at least comprises the optical characterization or processing unit (15).
24. The apparatus (10) according to any one of the preceding claims, further comprising at least one sensor for detecting contact or a collision between two subcomponents of the apparatus (10).
25. An object transport unit (55), comprising an object carrier (50) for receiving an object (60), at least one membrane (100) introduced between an objective (40) and the object carrier (50), wherein the membrane (100) has a portion (120) configured for penetration by light (140), wherein at least the portion (120) of the membrane (100) is movable in the axial direction with respect to the optical axis (502), and at least one membrane holder (80) for holding the at least one membrane (100), wherein the object transport unit (55) is at least transferable between a handling unit (200) for immersion media and an optical characterization or processing unit (15), wherein the handling unit (200) is at least configured to apply an immersion medium (160) used between the membrane (100) and an object (60) to be characterized or processed, and wherein the optical characterization or processing unit (15) comprises at least one device for producing or for receiving the light (140) and the objective (40) for exposing the object (60) using the light (140) or for capturing the light (140) from the object (60).
26. The object transport unit (55) according to the preceding claim, wherein the membrane holder (80) is fastened to the object transport unit (55) or integrated in the object transport unit (55).
27. The object transport unit (55) according to either of the two preceding claims relating to the object transport unit (55), wherein the object transport unit (55) is configured that the immersion medium (160) is fixated between the membrane (100) and the object (60).
28. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the object transport unit (55) is configured that the object (60) is transported from the handling unit (200) to the optical characterization or processing unit (15) using a conveyor system (210).
29. The object transport unit (55) according to the preceding claim, wherein a transport of the object (60) from the handling unit (200) to the optical characterization or processing unit (15) takes place under normal ambient conditions.
30. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the optical characterization or processing unit (15) is configured to apply a further index liquid (170) between the membrane (100) and the objective (40) before the processing and/or the optical characterization of the object (60) is implemented.
31. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the object transport unit (55) is configured that the object (60) is transferable to a separate developer unit (230) using a further conveyor system (210).
32. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the object transport unit (55) is configured to be opened in the developer unit (230).
33. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the membrane (100) is transparent to the light (140) at a wavelength used for the optical characterization or processing of the object (60) but is not transparent to the light at shorter wavelengths.
34. The object transport unit (55) according to any one of the preceding claims relating to the object transport unit (55), wherein the object transport unit (55) is designed as a closed container.
35. A method for optical characterization or processing of an object (60) using an apparatus (10) for optically characterizing or processing an object (60), comprising the following steps: a) positioning at least one object (60) on an object carrier (50); b) applying an immersion medium (160) to at least part of the object (60); c) approaching a membrane (100) to the part of the object (60) covered with the immersion medium (160), wherein the membrane (100) has a transparent portion (120) provided for light (140) to penetrate; d) positioning an objective (40), which defines an optical axis (502), relative to the part of the object (60) covered by the immersion medium (160); e) setting an axial position for the portion (120) of the membrane (100) with respect to the optical axis (502); and f) optically characterizing or processing the object (60) using the light (140).
36. The method according to the preceding claim, wherein axial positioning of the portion (120) of the membrane (100) penetrated by the light (140) is implemented together with the positioning of the objective (40) in a synchronized movement.
37. The method according to either of the preceding method claims, wherein luminescence radiation excited by the light (140) in the immersion liquid (160) is captured in order to set an axial position of the membrane (100).
38. The method according to any one of the preceding method claims, wherein steps a) to c) are carried out in a handling unit (200) for immersion media, which is configured to introduce the immersion medium (160) used between the membrane (100) and the object (60), wherein an object transport unit (55) at least comprising the object carrier (50), the membrane (100), and a membrane holder (80) configured to hold the membrane (100) is subsequently transferred to a lithography unit (220) which at least comprises an optical characterization or processing unit (15), and wherein steps d) to f) are carried out in the lithography unit (220).
Description
BRIEF DESCRIPTION OF THE FIGURES
[0091] Further details and features of the present invention are apparent from the following description of preferred exemplary embodiments, in particular in connection with the dependent claims. Here, the respective features can be implemented by themselves, or a plurality thereof can be implemented together in combination. The invention is not limited to the exemplary embodiments.
[0092] The exemplary embodiments are illustrated schematically in the following figures. Identical reference numerals in the figures refer to identical or functionally identical elements or to elements which correspond to one another in terms of their functions.
[0093] Specifically:
[0094] FIG. 1 shows a schematic illustration of a preferred exemplary embodiment of the apparatus according to the invention;
[0095] FIG. 2 shows a schematic illustration of particularly preferred exemplary embodiments of an objective for the apparatus according to the invention;
[0096] FIG. 3 shows a schematic illustration of an object which comprises a plurality of partial objects;
[0097] FIG. 4 shows a schematic illustration of a plurality of exemplary embodiments for membrane holder and positioning elements;
[0098] FIG. 5 shows a schematic illustration of a device comprising a plurality of apparatuses with separate functions, and an object transport unit;
[0099] FIG. 6 shows results of a simulation of the imaging quality of the apparatus according to the invention;
[0100] FIG. 7 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention which comprises a second membrane;
[0101] FIG. 8 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention, in which forces for the deformation and axial positioning of the membrane or of its transparent portion are introduced by a positioning element that is fastened to the objective stage or to the objective;
[0102] FIG. 9 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention, in which the membrane holder is fastened to the objective stage;
[0103] FIG. 10 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention, in which the membrane holder is likewise connected to the objective stage;
[0104] FIG. 11 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention, comprising a solid photoresist which covers the object;
[0105] FIG. 12 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention, in which the membrane has lateral structuring;
[0106] FIG. 13 shows a schematic illustration of a preferred exemplary embodiment of an arrangement for membrane holder and positioning; and
[0107] FIG. 14 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus according to the invention and the object transport unit, prior to an assembly in a plan view (FIG. 14a) and after the assembly in a plan view (FIG. 14b) and as a cross section (FIG. 14c).
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0108] FIG. 1 shows a schematic illustration of a preferred exemplary embodiment of the apparatus 10 according to the invention for optically characterizing or processing an object 60. The apparatus 10, illustrated in exemplary fashion in FIG. 1, comprises an object carrier 50 for receiving the object 60, an optical characterization or processing unit 15, which comprises a device for producing light, which is provided in this case in exemplary fashion in the form of at least one light beam 140 and which can therefore also be referred to as a “lithography unit”, and an objective 40 for exposing the object 60 using the light beam 140, a membrane 100 introduced between the objective 40 and the object 60, a membrane holder 80 for holding the membrane 100, and an immersion medium 160 which is introduced between the membrane 100 and the object 60. The membrane 100 comprises a portion 120 which is configured to be penetrated by the light beam 140 used for imaging or processing, wherein at least the portion 120 of the membrane 100 is arranged movably in the axial direction in relation to an optical axis 502, which is defined by the objective 40. To this end, at least one positioning element 90 can preferably be used to be able to move the portion 120 of the membrane 100 in the axial direction during the characterization or processing procedure. The objective 40 has an end face 46 which faces the object carrier 50, the end face 46 having an edge 47.
[0109] According to the invention, it is proposed to attach the membrane 100 to the membrane holder 80 in a manner that first contact points 81 between the membrane 100 and the membrane holder 80 are located on or outside a lateral surface 510 which is formed by a geometric extrusion of the edge 47 of the end face 46 of the objective 40 parallel to the optical axis 502. In this case, the geometric extrusion of the edge 47 of the end face 46 of the objective 40 parallel to the optical axis 502 in this case denotes an increase in the dimensionality of the edge 47 of the end face 46 of the objective 40 by way of a parallel displacement in space, parallel to the optical axis 502. In this way, the edge 47 of the end face 46 of the objective 40, which represents a line or a curve, is drawn in a manner along a direction parallel to the optical axis 502 that the desired lateral surface 510 is obtained by this process. Consequently, the lateral surface 510 describes the surface formed by the geometric extrusion of the edge 47 of the end face 46 of the objective 40 parallel to the optical axis 502. This lateral surface 510 can also be understood to be an enveloping surface of a cylindrical body which arises from a geometric extrusion of the end face 46 along the optical axis 502 and which, depending on a profile of the edge 47, can adopt any cross section, in particular in the form of a circle, an ellipse, or an oval. However, other shapes of the cross section are possible. This embodiment according to the invention of the present apparatus 10 consequently renders it possible to use the installation space available in the axial direction on or outside of the lateral surface 510 for the purposes of configuring the membrane holder 80, advantageously without in the process curtailing the usable working distance of the apparatus 10 by way of mechanical elements which, according to the prior art, would be introduced between the end face 46 of the objective 40 and the object 60.
[0110] FIG. 2 shows a schematic illustration of particularly preferred exemplary embodiments of the objective 40, which is provided for use in the apparatus 10 according to the invention.
[0111] Herein, FIG. 2a shows a cross section through the objective 40, said cross section showing the end face 46, the edge 47 of the end face 46, an exit window 48, and a mount 49 of the objective 40. In this case, the part of the mount 49 of the objective 40 facing the object 60 forms a ridgeline 500, which defines a contour surrounding the optical axis 502, which contour is formed by the points protruding furthest in the direction of the object 60 parallel to the optical axis 502. Preferably, the ridgeline 500 of the mount 49 of the objective 40 can be constructed as follows: Initially, intersections of the mount 49 with a manifold of half-planes 503, which start at the optical axis 502 and extend in the radial direction, are determined. In this case, the term “radial” is understood to be a direction that is perpendicular to the optical axis 502 and which is denoted in FIG. 2b by the coordinate r or the local unit vector e.sub.r; the axial direction extends parallel to the optical axis 502 and is denoted by the coordinate z and the local unit vector e.sub.z. The term “azimuthal”, the associated parameter φ and the associated local unit vector e.sub.v are used in accordance with the known definitions of polar coordinates in order to denote a direction oriented locally perpendicular to the radial and the azimuthal axes, wherein the direction emerges from the right hand property of the coordinate system (e.sub.r, e.sub.φ, e.sub.z). Combinations of radial and azimuthal directions are also referred to as “lateral” directions. Each of the intersections of the mount 49 with a half-plane 503 has a contour 504, from which the ridge point 501 belonging to the respective radial direction can be ascertained. For this purpose, the point 501 of the contour 504 which is closest to the surface 69 of the object 60 is determined under the assumption of an object 60 with a plane surface 69 that is perpendicular to the optical axis 502. Finally, the ridgeline 500 is formed by a set of the ridge points 501 belonging to the various radial directions. Moreover, the term end face 46 can be defined using the ridgeline 500 of the mount: The end face 46 at least comprises the exit window 48 of the objective 40. In the case of a mount 49 adjoining this exit window 48, the end face 46 additionally comprises the region of the mount 49 enclosed by the ridgeline 500 and all points outside of the ridgeline 500 which, in the case of a plane surface 69 of the object 60 aligned perpendicular to the optical axis 502, have a distance d′ from the object which is preferably greater than the maximum distance d of a point on the ridgeline 500 from the surface 69 of the object 60 by less than 5 mm, particularly preferably by less than 1 mm, in particular by less than 300 μm. In this case, the end face 46 of the objective 40 forms a simple contiguous area, which is delimited by the edge 47. According to this definition, the points of the end face 46 closest to the object 60 are therefore not necessarily located on the ridgeline 500 of the mount 49. A corresponding case is sketched out in FIG. 2d. FIG. 2d shows a schematic illustration of a particularly preferred exemplary embodiment of the apparatus 10, in which the objective 40 has a convexly curved exit window 48, while the exit window 48 is plane in FIGS. 2a to 2c. In the case of the convexly curved exit window 48 of the objective 40, the points closest to the object 60 can be located on the exit window 48 itself. However, the above-described definition of the end face 46 of the objective 48 remains untouched by this embodiment.
[0112] FIG. 2b illustrates a plan view of the end face 46 of the objective 40 parallel to the optical axis 502. In this case, the ridgeline 500, the end face 46, the edge 47, the exit window 48, and the mount 49 of the objective 40 are evident.
[0113] FIG. 2c shows a schematic illustration of a particularly preferred exemplary embodiment of the apparatus 10, which comprises the objective 40 from FIGS. 2a and 2b. In this case, a working distance d between the exit face 48 of the objective 40 and the surface of the object 60 is partitioned by the membrane 100 into a usable working distance d″ between the side of the membrane 100 facing the object 60 and the object 60.
[0114] FIG. 3 shows a schematic illustration of an object in the form of a multi-chip module 61, which comprises a plurality of partial objects 65, 66, 67, wherein the partial objects 65, 66, 67 are attached to a common base plate 68 and wherein, as illustrated in FIG. 3, the base plate 68 can be placed on the object carrier 50. Alternatively, the base plate 68 itself can form the object carrier 50 (not illustrated).
[0115] FIG. 4 shows a schematic illustration of a multiplicity of exemplary embodiments for the membrane holder 80 and the positioning elements 90. Moreover, further exemplary embodiments according to the invention which comprise further possible combinations of membrane holders 80, membrane fastening means, and positioning elements 90 are conceivable.
[0116] In the embodiment of FIG. 4a, the membrane holder 80 is fastened to the object carrier 50. In this case, the membrane holder 80 can be movably mounted by way of an actuator 180, in a manner that the membrane holder 80 can simultaneously serve as the positioning element 90 in this embodiment, the portion 120 of the membrane 100 penetrated by the light beam 140 being able to be moved axially therewith. In an alternative embodiment, the membrane holder 80 can be fastened to the object stage 51.
[0117] In the embodiment of FIG. 4b, the membrane holder 80 is fastened to the objective stage 20. In this case, the membrane holder 80 can be movably mounted by way of an actuator 180, in a manner that the membrane holder 80 can simultaneously serve as the positioning element 90 in this embodiment, in order to be able to axially move the portion 120 of the membrane 100 penetrated by the light beam 140.
[0118] In the embodiment of FIG. 4c), the membrane holder 80 is fastened to a further part of the lithography device 16. In this case, the membrane holder 80 can be movably mounted by way of an actuator 180, in a manner that the membrane holder 80 can simultaneously serve as the positioning element 90 in this embodiment, the portion 120 of the membrane 100 penetrated by the light beam 140 being able to be moved axially therewith. In contrast to the objective 40, the further part of the lithography device 16 is not a constituent part of the optical beam path and is therefore subject to lesser requirements in respect of precision and dynamics of the positioning than, for example, the objective, wherein the further part of the lithography device 16 used for fastening purposes can absorb at least some of the forces acting on the membrane 100.
[0119] In the embodiment of FIG. 4d), the membrane holder 80 is fastened to the objective stage 20. The positioning elements 90 are likewise fastened to the objective stage 20 and consequently allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective stage 20. In this case, the membrane holder 80 can preferably be fastened to the objective stage 20 using actuators 180 and/or by one or more rigid fastening elements.
[0120] In the embodiment of FIG. 4e), the membrane holder 80 is fastened to the objective stage 20 using one or more fastening elements 181. The positioning elements 90 are likewise fastened to the objective stage 20 using actuators 91, with the aid of which the portion 120 of the membrane 100 penetrated by the light can be moved axially.
[0121] In the embodiment of FIG. 4f), the membrane holder 80 is fastened to the objective stage 20. The positioning elements 90 are fastened to the objective 40 and allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective 40. In this case, the membrane holder 80 can preferably be fastened to the objective stage 20 using actuators 180 and/or by one or more rigid fastening elements.
[0122] In the embodiment of FIG. 4g), the membrane holder 80 is fastened to the objective stage 20 using one or more fastening elements 181. The positioning elements 90 are fastened to the objective 40 using additional actuators 91 and can, by way of the actuators 91, axially move the portion 120 of the membrane 100 penetrated by the light in relation to the objective 40.
[0123] In the embodiment of FIG. 4h), the membrane holder 80 is fastened to the objective stage 20 using one or more fastening elements 181. In this case, the objective 40 or a part of the objective 40, which can axially move the portion 120 of the membrane 100 penetrated by the light, serves as a positioning element 90. Second contact points 96 between the membrane 100 and the objective 40 can be formed by the edge 47 of the end face 46 of the objective 40, by the ridgeline 500 of the end face 46 of the objective 40, or by further constituent parts of the objective 40.
[0124] In the embodiment of FIG. 4i), the membrane holder 80 is fastened to the objective stage 20 using one or more fastening elements 181. In this case, the objective 40 or a part of the objective 40 serves as a positioning element 90 for axially moving the portion 120 of the membrane 100 penetrated by the light. If the objective 40 has a plane exit window 48 or an exit window 48 that is convexly arched in the direction of the object 60, the exit window 48 can have a shorter distance from the object 60 than the mount 49 of the objective 40; this also emerges from FIG. 2d. In the case of a flexible membrane 100, the latter can cling to the exit window 48 in the process.
[0125] In the embodiment of FIG. 4j), the membrane holder 80 is fastened to the object carrier 50 using one or more fastening elements 181. The positioning elements 90 are likewise fastened to the object carrier 50 using distinct actuators 91 and can, by way of these actuators 91, axially move the portion 120 of the membrane 100 penetrated by the light.
[0126] In the embodiment of FIG. 4k), the membrane holder 80 is fastened to the object carrier 50 using one or more fastening elements 181. The positioning elements 90 are fastened to the objective stage 20 and allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective stage 20. In a manner analogous to this embodiment, further embodiments that are similar to the embodiment of FIG. 4e) are conceivable, in which the positioning elements 90 are fastened to the objective stage 20 using distinct actuators 91.
[0127] In the embodiment of FIG. 4l), the membrane holder 80 is fastened to the object carrier 50 using one or more fastening elements 181. The positioning elements 90 are fastened to the objective 40 and allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective 40. In a manner analogous to this embodiment, further embodiments that are similar to the embodiment of FIG. 4g) are conceivable, in which the positioning elements 90 are fastened to the objective 40 by means is dedicated actuators 91.
[0128] In the embodiment of FIG. 4m), the membrane holder 80 is fastened to the object carrier 50 using one or more fastening elements 181. In this case, the objective 40 or a part of the objective 40, which can axially move the portion 120 of the membrane 100 penetrated by the light, serves as a positioning element 90. The contact points 96 between the membrane 100 and the objective 40 are formed by the edge 47 of the end face 46 of the objective 40, by the ridgeline 500 of the end face 46 of the objective 40, or by another constituent part of the objective 40. In a manner analogous to the embodiment of FIG. 4i), the exit window 48 can have a shorter distance from the object 60 than the mount 49 of the objective 40. In the case of a flexible membrane 100, the latter can cling to the exit window 48 in this case, too.
[0129] In the embodiment of FIG. 4n), the membrane holder 80 is fastened to the object carrier 50 using one or more fastening elements 181. The positioning elements 90 are fastened to a further part of the lithography device 16 using actuators 91 and can, with the actuators 91, axially move the portion 120 of the membrane 100 penetrated by light. In a manner analogous to this embodiment, embodiments in which the membrane holder 80 can be fastened to the objective stage 20, to the object stage 51, or to a further part of the lithography device 16 are also conceivable.
[0130] In the embodiment of FIG. 4o), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 are fastened to the objective stage 20 and allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective stage 20. In this case, the membrane holder 80 can be fastened using actuators 180 and/or by one or more rigid fastening elements.
[0131] In the embodiment of FIG. 4p), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 comprise actuators 91, which are fastened to the objective stage 20 and which facilitate an axial movement of the portion 120 of the membrane 100 penetrated by the light in relation to the objective 40.
[0132] In the embodiment of FIG. 4q), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 are fastened to the objective 40 and allow the portion 120 of the membrane 100 penetrated by the light to be moved axially in a synchronous fashion with the movement of the objective 40. In this case, the membrane holder 80 can preferably be fastened using actuators 180 and/or by one or more rigid fastening elements.
[0133] In the embodiment of FIG. 4r), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 comprise actuators 91, which are fastened to the objective 40 and which facilitate an axial movement of the portion 120 of the membrane 100 penetrated by the light in relation to the objective 40.
[0134] In the embodiment of FIG. 4s), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 comprise actuators 91, which are fastened to the object carrier 50 and which facilitate an axial movement of the portion 120 of the membrane 100 penetrated by the light.
[0135] In the embodiment of FIG. 4t), the membrane holder 80 is fastened to a further part of the lithography device 16. The positioning elements 90 comprise actuators 91, which are fastened to the same part of the lithography device 16 or to a further part of the lithography device 17 and which facilitate an axial movement of the portion 120 of the membrane 100 penetrated by the light.
[0136] FIG. 5 shows a schematic illustration of a device comprising a plurality of apparatuses 10, each of which can carry out a selected function. In a first device 200 embodied as a handling unit for immersion media, the immersion medium, for example in the form of an immersion liquid 160, can be applied to the object 60 using a dispensing unit 35. The handling unit 200 for immersion media can further be configured to surround the object provided with an immersion liquid 160 with an object transport unit 55, which is preferably configured as a closed container and which, for example, comprises a membrane holder 80, a membrane 100, an object carrier 50, and a fastening element 181, wherein alternative or additional use can be made of a movable element or an actuator 180 for fastening the membrane holder 80 to the object carrier 50. The object 60 or the object transport unit 55 can be transported under normal ambient conditions from the handling unit 200 to the lithography unit 220 using a conveyor system 210. In the lithography unit 220, a further index liquid 170 can optionally be applied between the membrane 100 and the objective 40 using a dispenser unit 30, before a processing of the object 60 and/or an optical characterization of the object 60 are carried out. In the case of lithographic processing, the object 60 or the object transport unit 55 can be transferred to a separate developer unit 230 using a further conveyor system 210 in a further step. In the developer unit 230, the object transport unit 55 can be reopened in order to remove non-polymerized parts of the photoresist from the object 60 using a rinsing unit 235. Other embodiments of the device comprising a plurality of apparatuses 10 and their respective function are possible.
[0137] The device schematically illustrated in FIG. 5 sketches a special case of an application of the apparatus 10 according to the invention and of a technical implementation of the method according to the invention, wherein the development steps following the lithographic processing need not necessarily be included. Since a particular advantage of the membrane 100 used according to the invention lies in sealing the volume of the immersion liquid 160 toward the objective 40, the membrane 100 can serve as protection for the immersion liquid 160 and the object 60 at the same time. Hence, the membrane 100 can adopt the function of a cover, which can preferably protect the object 60 and the immersion liquid in contact therewith from contamination, from contact with oxygen or with moisture in the air, or from unintentional exposure by short wavelength ambient light. In particular, the membrane can also be electrically conductive and protect the components from electrostatic discharge (ESD). To protect the object 60 and the immersion liquid 160 in contact therewith, these can be placed in an object transport unit 55, which, by way of the application of the membrane 100 and/or the membrane holder 80, is configured to be a container that is sealed to the best possible extent. The exemplary container schematically illustrated in FIG. 5 in this case comprises the object carrier 50, the fastening element 181 which is integrated in a sidewall 52 of the object carrier 50 or which forms said sidewall, the membrane holder 80, and the membrane 100, wherein the container is configured to receive the object 60 and the immersion liquid 160. A clear space remaining in the container can optionally be filled with a protective gas in order to avoid contact between the immersion liquid 160 and oxygen or moisture present in the ambient atmosphere. By using the object transport unit 55 with a protective function, the individual steps for optically characterizing or processing the object 60 can be carried out in functional units that are spatially separated from one another, wherein the object 60, together with the immersion liquid 160, is preferably transferable under normal ambient conditions between the functional units so that, as mentioned above, there is no need for particular requirements in respect of cleanliness (e.g., cleanroom classes), exposure (e.g., so-called yellow light surroundings), atmospheric boundary conditions (e.g., regulated humidity), and/or ESD protection in the traversed spatial region. The transfer of the object 60 protected by the membrane 100 between the various functional units is particularly advantageous in view of the design of industrial manufacturing systems, since a specialist device can be used for each step and since, in particular, this allows the optical lithography processes to be separated from wet chemical processes.
[0138] FIG. 6 shows results of a simulation of the imaging quality of the apparatus 10 according to the invention. In this case, the apparatus 10 comprises the objective 40 and the membrane 100, which separates two different immersion liquids, for example a photoresist 160 and an immersion liquid 170, from one another. Within the scope of the simulation, focusing of the light 140 was simulated by ray optics on the object side and represented by a so-called “spot diagram”. The spot diagram shows the position of various rays of a beam in the focal plane of the objective 40. The region within the respectively plotted solid circle denotes the diffraction limit. In the simulation of FIG. 6a), the refractive index 1.52 of both immersion liquids 160, 170 is well-matched to the objective 40, and so a diffraction limited focus is almost obtained. In the simulation of FIG. 6b), there is an intentional or unintentional change in the refractive index of the immersion liquid 160 to 1.53, for example as a result of aging or due to the use of a different substance with a slightly deviating composition. In the case of the same position of the membrane 100, the focus has now become significantly larger and is no longer diffraction-limited. However, by displacing the membrane 100 in accordance with the simulation of FIG. 6c), it is possible to once again obtain a diffraction-limited focus and the change of the refractive index to 1.53 can be compensated for therewith. Thus, an optimal setting of the axial position of the membrane 100 allows aberrations to be compensated for, for example aberrations arising from slight variations of the refractive index of the photoresist that is used as immersion medium in the case of lithography.
[0139] FIG. 7 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, which has a second membrane 105 that is fastened to a second membrane holder 85. In this case, a further immersion liquid 175 is used in addition to the immersion liquid 170 or the combination of the photoresist 160 and the immersion liquid 170. The immersion liquids 170, 175 and the photoresist 160 can have different refractive indices, dispersion characteristics and/or viscosities, as a result of which additional degrees of freedom are enabled during the compensation of aberrations. At least one of the membranes 100, 105 can be positioned in the axial direction by the at least one positioning element 90.
[0140] FIG. 8 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, in which forces for deforming and for axially positioning the membrane 100 or the light-penetrated portion 120 of the membrane 100 are introduced by way of a positioning element 95, which is connected to the objective stage 20 or to the objective 40. Rollers or sliding surfaces on the contact points 96 between the positioning element 95 and the membrane 100 can ensure low friction in the case of a lateral movement of the membrane 100 relative to the positioning elements 95.
[0141] FIG. 9 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, in which the membrane holder 80 is fastened to the objective stage 20. In this case, the membrane holder 80 comprises an arrangement of rollers and/or sliding surfaces 85, which are fastened to the objective stage 20 by fastening elements 185 and which facilitate an automated removal and supply of further regions, in particular cleaner regions, of the membrane 110. The axial positioning of the light-penetrated portion 120 of the membrane 100 can be implemented by way of a mechanism in the membrane holder 80 in this case, for example by tensioning the rollers 85. As an alternative or in addition thereto, use can be made of positioning elements 90 in order to set the axial position of the light-penetrated portion 120 of the membrane.
[0142] FIG. 10 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, in which the membrane holder 80 is likewise fastened to the objective stage 20. This can preferably facilitate the use of various objectives 40, 41, 42, which are exchangeable using a revolver mechanism 45, for example, without this changing the position of the membrane 100. The light-penetrated portion 120 of the membrane 100 can be positioned by way of movable elements 180 or actuators. A further immersion liquid 170 that is optionally used between the membrane 100 and the respective objective 40, 41, or 42 in use can be supplied following an exchange of the objective 40, 41, or 42 by way of a dispenser unit (not illustrated) that is integrated in the lithography unit 220.
[0143] FIG. 11 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, which comprises a solid photoresist 161 which covers the object 60. What emerges from FIG. 11a) is that a first index liquid 160, which is matched to the refractive index of the solid photoresist, represents a defined optical interface together with the membrane 100 so that the light 140 can be input coupled via a dry objective. According to FIG. 11b), a further immersion liquid 170 can be used between the membrane and the objective 40 in order to attain a high NA and/or in order to compensate for aberrations arising from a refractive index mismatch. As an alternative or in addition thereto, the further immersion liquid 170 can also have a viscosity that differs from that of the first index liquid 160.
[0144] FIG. 12 shows a schematic illustration of a further, preferred exemplary embodiment of the apparatus 10 according to the invention, in which the membrane 100 has lateral structuring 110. The lateral structuring 110 of the membrane 100 can be used to optimize wetting properties of the membrane 100 in respect of one or more immersion liquids 160, 170. In a further embodiment, one or more guide elements 115 can be used to curtail a lateral spread of the immersion liquid 170.
[0145] FIG. 13 shows a schematic illustration of a preferred exemplary embodiment of an arrangement for a preferred membrane holder 300 and its positioning. The exemplary embodiment of FIG. 3 is based on the exemplary embodiment of FIG. 4b, with rigid fastening elements 181 being used here in place of the actuators 180. A membrane 100, which is preferably provided in the form of a thin film (not illustrated here), is placed over an inner ring 330. In this case, an outer ring 340 is placed over the inner ring 330 for fixing the membrane 100. The conic surfaces 345 in the inner ring 330 and on the outer ring 340 allow films with different thicknesses to be tensioned. In this case, the outer ring 340 is fixed to the inner ring 330 by clamping or by screws in corresponding threaded holes 350, for example. A further clamping apparatus 310 can serve to fasten the membrane holder 300 to the objective stage 20. Rigid webs 320 can connect the clamping apparatus 310 to the inner ring 330 of the membrane holder 300. The clamping apparatus 310 which is open on one side allows the holder 300 and the membrane 100 to be replaced, without needing to remove the objective 40. The membrane holder 300 can simply be pushed over the objective stage 20 in order thus to position the membrane 100 under the objective 40. The membrane holder 300 is formed by the rings 330, 340 while the webs 320 represent the rigid fastening elements 181. The axial positioning of the light-penetrated portion 120 of the membrane 100 is implemented here either by the membrane holder 300 on its own or by the edge 47 or the ridgelines 500 of the objective 40.
[0146] The exemplary embodiment of FIG. 13 can be extended to the effect of one of the fastening elements 181 or the objective stage 20 being provided with a sensor (not illustrated), using which possible collisions of the membrane holder 300 or of the membrane 100 with the object 60 or the object carrier 50 can be captured before the substantially more sensitive objective 40 is contacted or damaged. By way of example, unwanted contact or an unwanted collision between two components can be detected by a mechanical sensor or by an electrical sensor, which preferably can capture an electrical resistance between the two components and can identify contact or collision by way of a reduction in the electrical resistance. The use of a membrane 100 with a sufficient electrical conductivity can lend itself to this process, said membrane facilitating a detection of contact or a collision of the membrane with another subcomponent of the apparatus 10.
[0147] FIG. 14 shows a schematic illustration of a further, preferred exemplary embodiment 400 of the apparatus 10 according to the invention. In this case, the object 60 is situated on an object carrier 50, which can be covered by a membrane 100 which is tensioned in a ring holder 420. The plan view of FIG. 14a) shows this embodiment prior to assembly. In the plan view of FIG. 14b), the membrane 100 together with the object carrier 50 form an object transport unit 55 embodied as a closed container, which is able to protect the object 60 and the immersion liquid 160 previously applied to the object 60 from ambient influences. FIG. 14c) shows a cross section through the apparatus 10 according to the invention, in which the at least one positioning element 90 is able by way of an elastic deformation of the membrane 100 to set an optimal working distance between the object 60, the objective 40, and the membrane 100. In an alternative embodiment (not illustrated), the axial positioning of the light-penetrated portion 120 of the membrane 100 can also be achieved by the edge 47 or the ridgelines 500 of the objective 40, and so it is possible to dispense with additional positioning elements 90 that are attached to the objective 40.
[0148] On the basis of the illustration in FIG. 14, it is possible to sketch out an exemplary embodiment for a use of the method according to the invention in 3D lithography. The object 60 is fastened to the object carrier 50 according to step a). According to step b), a photoresist as the immersion medium 160 for two-photon polymerization is applied to the object 60 in a first functional unit. This is implemented manually or using a separate dispenser 35, which can additionally provide an inert gas atmosphere. Following the application of the immersion liquid, the membrane 100, which is fastened to a ring holder 420, is attached to the object carrier 50 in the first functional unit, according to step c), in a manner that the latter is preferably sealed in air-tight fashion. As a result, in a manner analogous to the exemplary embodiment according to FIG. 5, an object transport unit 55 is provided, which is able to protect the object 60 from the ambient atmosphere. If use is made of a membrane 100 that is not transparent in the UV range, the object 60 can also be transported through regions in which no pure yellow light illumination is provided. If use is made of an electrically conductive membrane 100, the object 60 can also be transported through regions which are not ESD-protected; to this end, the object transport unit 55 should be designed accordingly. Following this, the object carrier 50 with the membrane 100 is transferred into a further functional unit which is embodied as a lithography unit 220, in which the lithographic processing and/or the optical characterization occurs. The object transport unit 55 continues to be closed in this functional unit and, optionally, a second immersion liquid 170 is applied between the membrane 100 and the objective 40. Thereafter, the objective 40 is caused to approach the membrane 100 according to step d). Since the ring holder 420 has a greater diameter than the objective 40, the light-penetrated portion 120 of the membrane 100 can be brought, synchronously with the axial movement of the objective 40, into an advantageous position between the object 60 and the objective 40 by the positioning elements 90, which are fastened to the objective 40 in this case. Once the desired axial position between the objective 40 and the object 60 has been reached according to step e), the processing and/or characterization of the object 60 can now be implemented according to step f), wherein the processing can comprise 3D patterning using 3D lithography, in particular. Partial steps e) and f), which comprise the positioning of the membrane 100 and the patterning of the object 60, can be carried out once or multiple times, for example at different positions of the object 60 and hence at different positions of the membrane 100. After the 3D lithography has been implemented according to step f), the object transport unit 55 remains closed and is transferred to a further functional unit embodied as a developer unit 230. In this functional unit, the membrane 100 with the ring holder 420 can be taken away and the non-polymerized photoresist can be removed in a development process.
LIST OF REFERENCE SIGNS
[0149] 10 Apparatus [0150] 15 Optical characterization or processing unit (lithography unit) [0151] 16, 17 Further part of the lithography unit [0152] 20 Objective stage [0153] 30 Dispenser unit [0154] 40, 41, 42 Objective [0155] 45 Revolver mechanism [0156] 46 End face [0157] 47 Edge [0158] 48 Exit window [0159] 49 Mount [0160] 50 Object carrier [0161] 51 Object stage [0162] 52 Sidewall of the object carrier [0163] 55 Object transport unit [0164] 60 Object [0165] 61 Multi-chip module [0166] 65, 66, 67 Partial object [0167] 68 Base plate [0168] 69 Surface of the object [0169] 80, 85 Membrane holder [0170] 81 First contact point [0171] 85 Rollers and/or sliding surfaces [0172] 90, 95 Positioning element [0173] 91 Actuator [0174] 96 Second contact point [0175] 100, 105 Membrane [0176] 110 Lateral structuring [0177] 115 Guide element [0178] 120 Light-penetrated portion [0179] 130 Part of the object [0180] 140 (Laser) light [0181] 160, 170, 175 Immersion medium (immersion liquid, photoresist) [0182] 161 Solid photoresist [0183] 180 Movable element (actuator) [0184] 181, 185 Fastening element [0185] 200 Dispenser [0186] 210 Conveyor system [0187] 220 Lithography unit [0188] 230 Developer unit [0189] 235 Rinsing unit [0190] 300 Membrane holder [0191] 310 Clamping apparatus [0192] 320 Web [0193] 330 Inner ring [0194] 340 Outer ring [0195] 345 Conic surfaces [0196] 350 Threaded hole [0197] 400 Further preferred exemplary embodiment [0198] 420 Ring holder [0199] 500 Ridgeline [0200] 501 Ridge point [0201] 502 Optical axis [0202] 503 Half-plane [0203] 504 Contour [0204] 510 Lateral surface
