Markup system for optical system, carrier substrate, and method for manufacturing of same

Abstract

Disclosed is a system for and a method of manufacturing of an optical system, including a first optical component, comprising a first waveguide and a carrier substrate, wherein the first optical component is arranged on the carrier substrate. The first optical component comprises a first markup set having a defined position/orientation with respect to the first waveguide, the carrier substrate has a second markup set detectable based on a relative position/orientation of the first and second markup sets when a desired orientation of the first waveguide relative to the carrier substrate is achieved in a reference plane extending parallel to a surface of the carrier substrate.

Claims

1. An optical system, including: a first optical component, comprising a first waveguide; and a carrier substrate, wherein the first optical component is arranged on the carrier substrate; wherein the first optical component comprises a first markup set having a at least one of defined position or orientation with respect to the first waveguide, the carrier substrate has a second markup set detectable based on at least one of a relative position or orientation of the first markup set and the second markup set when a desired orientation of the first waveguide relative to the carrier substrate is achieved in a reference plane extending parallel to a surface of the carrier substrate.

2. The optical system according to claim 1, further including a second optical component which is arranged on the carrier substrate and comprises a second waveguide which can be optically coupled to the first waveguide.

3. The optical system according to claim 2, wherein the second optical component comprises a third markup set having at least one of a defined position or orientation with respect to the second waveguide detectable based on at least one of a relative position or orientation of at least two of the markup sets if the first optical component and the second optical component are oriented relative to each other in a reference plane extending parallel to a surface of the carrier substrate in such the first waveguide and the second waveguide are optically coupled.

4. The optical system according to claim 3, wherein the first waveguide has a first distance from the front side of the first optical component, the second waveguide has a second distance from a front side of the second optical component, where the front side of the first optical component and the front side of the second optical component are facing the carrier substrate, and the first distance and the second distance are selected such that at least one of a relative position or orientation of the first and second optical components to each other in a normal direction oriented perpendicular to a surface of the carrier substrate is set in such that the first and second waveguides are optically coupled.

5. The optical system according to claim 2, wherein the second optical component further comprises: a recess through which the second optical component at least partially passes from a front side in the direction of a rear side located opposite the front side, wherein the first optical component is arranged in the recess.

6. The optical system according to claim 2, wherein the carrier substrate of the first optical component and the second optical component is removable and wherein a gap between the first waveguide and the second waveguide is filled with an optical filler material, and wherein a gap between the first optical component and the second optical component is filled with a casting compound.

7. The optical system according to claim 2, wherein a sacrificial structure is attached on a rear side of the first optical component facing away from the carrier substrate, wherein an auxiliary carrier with a recess for receiving the carrier substrate is attached on a front side of the second optical component facing the carrier substrate, and wherein surfaces of the first and second optical components are back thinned on a shared rear side.

8. The optical system according to claim 1, wherein the carrier substrate is at least partially transparent or translucent in a specific wavelength range, wherein the wavelength range is at least one of a range of visible, ultraviolet, or infrared wavelengths.

9. The optical system according to claim 1, wherein at least a portion of at least one of the markup sets is realized by a portion of at least one of the waveguides or contains the same, wherein at least a portion of at least one of the markup sets is an edge of at least one of the optical components, the carrier substrate, or contains the same, wherein at least a portion of at least one of the markup sets is deposited by a lithographic method onto at least one of the optical components, the carrier substrate, or is embedded in the same, and wherein at least a portion of at least one of the markup sets and at least a portion of at least one of the waveguides are produced by at least one of a lithographic method in a joint operation or using a shared mask.

10. The optical system according to claim 1, wherein at least one of the markup sets comprises at least one of a linear, a cross-shaped, a circular, an elliptical, or a polygonal element, or at least one of two or more parallel lines or a vernier scale structure.

11. The optical system according to claim 1, wherein at least one of the carrier substrate or at least one of the optical components comprises an adhesive layer adapted for at least one of a temporary or permanent fastening of at least one of the first or second optical component to the carrier substrate.

12. The optical system according to claim 11, wherein the adhesive layer is at least one of structured or not continuous, and wherein the first waveguide and second waveguide are oriented relative to each other under a partial deformation of the adhesive layer.

13. A carrier substrate comprising: a markup set and adapted for depositing an optical component thereupon, comprising: a waveguide; and a markup set having at least one of a defined position or orientation with respect to the waveguide in such a manner the markup set is detectable based on at least one of a relative position or orientation of at least a second markup set when a desired orientation of the waveguide relative to the carrier substrate is achieved in a reference plane extending parallel to a surface of the carrier substrate.

14. A method for manufacturing an optical system, comprising: providing at least one optical component, including at least one waveguide and a carrier substrate; and arranging the at least one optical component on the carrier substrate; wherein the at least one optical component comprises a respective markup set having at least one of a defined position or orientation with respect to at least one waveguide, and wherein the carrier substrate comprises a second markup set, and arranging the at least one optical component on the carrier substrate includes: detecting at least one of a relative position or orientation of the markup set of the at least one optical component with respect to the second markup set of the carrier substrate for orienting the waveguide of the at least one optical component relative to the carrier substrate in a reference plane extending parallel to a surface of the carrier substrate.

15. The method for manufacturing an optical system according to claim 14, further comprising: removing the carrier substrate from the at least one optical component after orienting the at least one optical component relative to the carrier substrate.

16. The method for manufacturing an optical system according to claim 15, wherein providing the at least one optical component comprises providing a first optical component and a second optical component and the method further comprises: filling a gap between the first waveguide and the second waveguide with an optical filler material; and filling a gap between the first optical component and the second optical component with a casting compound.

17. The method for manufacturing an optical system according to claim 16, further comprising: back thinning of a surface of the first optical component and a surface of the second optical component into a shared rear side depositing an electrical contact on a common front side of the first optical component and the second optical component; attaching a sacrificial structure on a rear side of the first optical component facing away from the carrier substrate; and attaching an auxiliary carrier with a recess for receiving the carrier substrate on a front side of the second optical component facing the carrier substrate.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Exemplary embodiments of the disclosure are explained in the following by means of FIG. 1 to FIG. 7b. The following is shown schematically in each case:

(2) FIG. 1a a cross-section of an optical system with a first optical component and a carrier substrate;

(3) FIG. 1b a cross-section of a second optical component;

(4) FIG. 2 a top view of a further example of an optical system;

(5) FIG. 3a to FIG. 3e cross-sections of the carrier substrate shown in FIG. 1b during various steps of a method for producing the optical system shown in FIG. 2;

(6) FIG. 4a to FIG. 4c cross-sections of a carrier substrate according to a further example in method steps according to another example;

(7) FIG. 5a to FIG. 5e cross-sections of the carrier substrate shown in FIG. 1b during various steps of a method for producing the optical system shown in FIG. 2 in various examples;

(8) FIG. 6a to FIG. 6d cross-sections of the optical components and the carrier substrate according to FIG. 1a and FIG. 1b as well as components of a processing device during various steps of a method for producing the optical system shown in FIG. 2, wherein the optical system shown in FIG. 1a represents an intermediate step;

(9) FIG. 7a the optical system according to FIG. 2 during a method step;

(10) FIG. 7b to FIG. 7e the optical system according to FIG. 2 during various steps of a method for the production thereof according to further examples.

DETAILED DESCRIPTION

(11) Repeating and similar features of various examples and embodiments are indicated in the following with the same reference numerals.

(12) The optical system 400 shown in cross-section in FIG. 1a has a first optical component 100 and a carrier substrate 300.

(13) The first optical component 100 has a first waveguide 101, which is formed between a first substrate layer 102 and a second substrate layer 103, wherein the substrate layers, 102 and 103, are implemented in a III/V material system and/or semiconductor material system. The first substrate layer 102 is arranged on a front side 104 of the first optical component 100, and the second substrate layer 103 is arranged on a back side 105 of the first optical component 100, said back side being opposite the front side 104. The first waveguide 101 exits into end surfaces 109 of the first optical component 100, which is perpendicular to the front side 104.

(14) The first optical component 100 is attached to a glass wafer which serves as the carrier substrate 300 and which is transparent for ultraviolet, visible, and infrared wavelengths (for example, a wavelength range of from 200 nm to 1200 nm or also only for subranges, for example of 400 to 800 nm) by means of an adhesive layer 301. The carrier substrate 300 has a front side 304 facing the first optical component 100 and a back side 305 opposite the front side 304.

(15) The first optical component 100 has a first marker set 110 with a defined position and orientation with respect to the first waveguide 101, and the carrier substrate 300 has a second marker set 310. As explained further below, it can be determined whether a desired alignment of the first waveguide 101 with respect to the carrier substrate 300 is produced in a reference plane parallel to a surface of the carrier substrate 300 by means of a relative position and/or orientation of the first and second marker set, 110 and 310.

(16) The second optical component 200 shown in cross-section in FIG. 1b is implemented as a photonic integrated circuit (PIC). The second optical component 200 has a second waveguide 201, which is formed as a nitride waveguide (based on SiNx) in an SiO2 layer in the example shown. The SiO2 layer 202 containing the second waveguide is arranged on a silicon layer 203. The second waveguide 201 may also be formed in a different manner, for example by means of lithographic structuring of a further silicon layer arranged on the SiO2 layer 202 (silicon-on-insulator architecture, SOI). The second waveguide 201 may optionally be supported in addition by thin oxide passivation.

(17) The SiO2 layer 202 is arranged on a front side 204 of the second optical component 200, and the silicon layer 203 is arranged on a back side 205 of the second optical component 200, said back side being opposite the front side 204. The second waveguide 201 exits into end surfaces 209 of the second optical component 200, which is perpendicular to the front side 204.

(18) Those end surfaces 209, at which the second waveguide 201 is intended to be optically coupled to the first waveguide 101, are prepared through mechanical polishing or through lithographically defined dry etching or through targeted local dry etching. Alternatively, the end surfaces 209 can be prepared, for example, through refraction along defined crystal surfaces.

(19) Layers 101 and 202 on the front side are prepared through depositing processes such that precisely defined layer thicknesses result.

(20) The second optical component 200 has a recess 206, which partially extends through the second optical component 200 from the front side 204 in the direction of the back side 205. Alternatively, it can also pass completely through the second optical component 200. The recess 206 can also be omitted. In this case, the optical components, 100 and 200, are arranged next to one another instead of within one another.

(21) The second optical component 200 has a third marker set 210 with a defined position and/or orientation with respect to the second waveguide 210.

(22) The optical components, 100 and 200, as well as the carrier substrate 300 may also be formed in different ways and/or from different materials as previously described by example. For example, at least one of optical components 100 and 200 may have a semiconductor chip (e.g. a silicon chip), a photonic integrated circuit (PIC), a silicon-on-insulator chip, a ceramic chip, and/or a glass chip. Furthermore, the carrier substrate 300 may contain materials such as silicon or other semiconductor materials, ceramics, glass, or polymer or consist thereof. At least one of the waveguides, 101 and 201, may contain a polymer, a glass, an oxide (e.g. SiO2), a nitride (e.g. Si3N4 in SiO2), and/or silicon (e.g. as Si on Si02).

(23) The further exemplary embodiment of an optical system 400 shown in a top view in FIG. 2 comprises the second optical component 200 (indicated by the dotted outlines) with the recess 206, the first optical component 100 (indicated by a solid outline), and the carrier substrate 300 (indicated by the dashed outline).

(24) The first optical component 100 has a first marker set 110 with a defined position and orientation with respect to the first waveguide 101. The carrier substrate 300 has a second marker set 310. The second optical component 200 has a third marker set 210 with a defined position and orientation with respect to the second waveguide 201. By means of a relative position and orientation of pairs (110/310, 210/310, 110/210) of the marker sets, it can be determined whether the first and second optical component, 100 and 200, are aligned with respect to one another in the reference plane such that an optical coupling is enabled between the first and second waveguide, 101 and 201.

(25) To this end, the third marker set 210 has a first part, which is formed from linear elements extending parallel to the second waveguide 201 and at fixed distances, and a second part, which is formed from linear, square, and cruciform elements, which are complementary to a first part of the second marker set 310. Complementary in this case means that elements of the corresponding parts of both marker sets, 210 and 310, supplement one another and/or have boundary lines parallel to one another due to super-position into contiguous shapes, when a desired relative alignment is present.

(26) In a corresponding manner, the first marker set 110 also has a first part, which is formed from linear elements extending parallel to the first waveguide 101 and at fixed distances, and a second part, which is formed from linear, square, and cruciform elements, which are complementary to a second part of the second marker set 310.

(27) The marker sets 110, 210, 310 may also, of course, be structured differently, for example at least one of them may have at least one round and/or elliptical and/or polygonal, e.g. rectangular, element and/or a vernier structure. The edges, which are formed by the optical components, 100 and 200, at the end surfaces, 109 and 209, in the region of the markers sets, 110 and 210, can be considered part of the markers sets, because they have defined points of intersection with the linear elements of the vernier structures.

(28) The marker sets, 110, 210, and 310, are implemented as structured metal layers, which are applied to the front sides, 104, 204, and 304. The markers sets 110, 210, 310 may also be implemented in a different manner; for example, markers sets 110 and 210 can be produced with the respective waveguides, 101 and 201, each in a common work step, and by means of a common mask, due to a lithographic process, i.e. can be embedded in the optical components, 100 and 200, in the same plane as the waveguides, 101 and 201. Furthermore, the waveguides, 101 and 201, themselves can serve as marker sets or parts of markers sets, provided they are readily visible.

(29) The adhesive layer 301 is implemented as a structured adhesive layer. Alternatively, it can be implemented also as a continuous layer.

(30) Exemplary steps of the method for producing the optical system 400 are described in the following by means of FIG. 3a to FIG. 7f. The method comprises providing the first optical component 100, the second optical component 200, and the carrier substrate 300.

(31) FIG. 3a to FIG. 3e show the carrier substrate 300 in various steps of its preparation, which may be part of the method for producing the optical system 400. The glass wafer, which serves as the carrier substrate 300 (FIG. 3a) is initially provided with a continuous metal layer 311 (FIG. 3b), which is subsequently structured by means of a lithographic process, whereby the second marker set 310 (FIG. 3c) is formed.

(32) Subsequently, an adhesive layer 301 is applied (FIG. 3d), which can be structured by means of a lithographic process and/or dry etching process and/or ablation process, whereby discrete adhesive structures 302 result (FIG. 3e). The adhesive structures 302 are preferably arranged in regions of the carrier substrate 300 outside of the second marker set 310.

(33) FIG. 4a to FIG. 4c show a further example of a carrier substrate 300 in various steps of its preparation. The glass wafer, which serves as the carrier substrate 300 and can be provided with the second marker set 310 and the structured adhesive layer 302, is provided with a continuous optically transparent polymer layer 320 (FIG. 4a). The polymer layer 320 is subsequently structured by means of a lithographic process, whereby a set of carrier substrate waveguides 321 (FIG. 4b, bottom) is formed. FIG. 4c shows the thusly prepared carrier substrate 300 in an exemplary method step, in which the first optical component 100 is arranged on the carrier substrate 300 such that an optical coupling is established between the first waveguide 101 and the carrier substrate waveguides 321.

(34) FIG. 5a to FIG. 3c show the second optical component 200 in various steps of its preparation, which may be part of the method for producing the optical system 400. In this case, the second optical component 200 is arranged with its back side 205 on a carrier 500. After application of a mask 220 to the front side 204, trenches 221 are etched into the second optical component 200, wherein a core 222 remains. The mask may preferably be removable and/or be a lithographically structured layer (metal layer, passivation layer, polymer (photo)resist). After removal of the core 222 and optionally of the carrier 500 as well as of the mask 220, the second optical component 200 has a shape similar to that shown in FIG. 1b (but with a continuous recess 206), which is prepared for the further method steps.

(35) FIG. 5d and FIG. 5e show the second optical component 200 in preparation steps according to a further example. The procedure is substantially as previously described in this case, but the mask 220 is designed such that the recess 206 is etched directly—i.e. without the intermediate step of providing trenches.

(36) FIG. 6a to FIG. 6d show exemplary steps of the arranging of the first and second optical component, 100 and 200, on the carrier substrate 300 such that the first optical component 100 is arranged in the recess 206 of the second optical component 200, as well as of the aligning of the first and second optical component, 100 and 200, with respect to one another, wherein a flip chip bonder 600 is used as the processing device.

(37) The flip chip bonder 600 comprises: a lower component carrier or chuck 601, an upper component carrier or bonding arm 602, a turning carrier or flip arm 603, and a camera system 604.

(38) The chuck 601 is configured for retaining and/or three-dimensionally moving a structural element on a side facing the bonding arm 602. The bonding arm 602 is configured for retaining and/or three-dimensionally moving a structural element on a side facing the chuck 601. The flip arm 603 is configured to accommodate a structural element and/or to turn it 180° and/or to transfer it to the chuck 601 or to the bonding arm 602. The camera system 604 may be arranged between the chuck 601 and the bonding arm 602 and is configured to simultaneously depict a part of a structural element retained by the chuck 601 and a part of a structural element retained by the bonding arm 602 (depiction directions are indicated by arrows), which can also be achieved, for example, by means of two lenses in conjunction with two sensors or one sensor and one optical splitter.

(39) In the method step shown in FIG. 6a, the chuck 601 retains the carrier substrate 300, and the bonding arm 602 retains the first optical component 100 such that the front sides, 104 and 304, are facing each other.

(40) At the same time, a part of the first marker set 110 and a part of the second marker set 310 are depicted by means of the camera unit 604, which enables a detecting of a relative position and orientation of the first optical component 100 and of the carrier substrate 300, or more precisely of a deviation from a desired relative position and orientation. Due to the movement of the chuck 601 and/or the bonding arm 602, the first optical component 100 and the carrier substrate 300 are then aligned with respect to one another (indicated by dashed lines).

(41) As shown in FIG. 6b, the front sides, 204 and 304, are subsequently brought together (after removal of the camera unit 604) through movement of the chuck 601 and/or of the bonding arm 602, while retaining the desired relative position and orientation, until the first optical component 100 is arranged on the carrier substrate 300 and attached by means of the adhesive layer 301. In this case, the adhesive layer 301 is partially deformed through pressing to the extent that the marker sets, 110 and 310, and/or the front sides, 104 and 304, act as reference surfaces.

(42) At this point, the mounting of the first optical component 100 on the carrier substrate 300 can be further evaluated in a control step. By means of the optically transparent carrier substrate 300, the relative positions and/or orientations of the first optical component 100, the second optical component 200, and the carrier substrate 300 can be detected, after removal of the bonding arm 602, through the detecting of parts of the marker sets 110, 210, 310 by means of the camera unit 604.

(43) The carrier substrate 300 with the first optical component 100 thereupon is turned by means of the flip arm 603 and transferred to the bonding arm 602. The second optical component 200 is then placed on the chuck 601, wherein the front side 204 of said component is facing the front side 304 of the carrier substrate 300 and the back side 105 of the first optical component 100 arranged thereupon.

(44) The thusly produced situation is shown in FIG. 6c. At the same time, a part of the third marker set 210 and a part of the second marker set 310 are then depicted by means of the camera unit 604, which enables a detecting of a relative position and orientation of the second optical component 200 and of the carrier substrate 300, or more precisely of a deviation from a desired relative position and orientation. Due to the movement of the chuck 601 and/or the bonding arm 602, the second optical component 200 and the carrier substrate 300 are then aligned with respect to one another (indicated by dashed lines). Because the first optical component 100 is already aligned with respect to the carrier substrate 300 due to the preceding steps, an alignment of the first and second optical component, 100 and 200, with respect to one another is also achieved.

(45) As shown in FIG. 6d, the front sides, 204 and 304, are subsequently brought together (after removal of the camera unit 604) through movement of the chuck 601 and/or of the bonding arm 602, while retaining the desired relative position and orientation, until the second optical component 200 is arranged on the carrier substrate 300 and attached by means of the adhesive layer 301, as well as the first optical component 100 is arranged in the recess 206 of the second optical component 200. In this case, the adhesive layer 301, in turn, is partially deformed through pressing to the extent that the marker sets, 210 and 310, and/or the front sides, 204 and 304, act as reference surfaces.

(46) By means of the optically transparent carrier substrate 300, the relative positions and orientations of the first optical component 100, the second optical component 200, and the carrier substrate 300 can be detected, after removal of the bonding arm 602, through the detecting of parts of the marker sets 110, 210, 310 by means of the camera unit 604. The result of the alignment can hereby be checked; if the accuracy of the alignment is outside of a specified tolerance, the preceding method steps may optionally be repeated, or the workpiece can be rejected.

(47) It should be mentioned that individual or all method steps can also, of course, be executed in a different manner or in a different sequence. For example, initially the second optical component 200 can be arranged and aligned on the carrier substrate 300, and subsequently the first optical component 100 can be placed in the recess 206 of the second optical component 200, provided the recess 206 passes completely through the second optical component 200.

(48) FIG. 7a shows the optical system 400 as it is after the preceding steps with the first optical component 100, the second optical component 200, and the carrier substrate 300 (without the processing device 600 at this point). Due to the precise, defined layer thicknesses of the front-side layers, 102 and 202, a first distance is set between the front side 104 of the first optical component 100 and the first waveguide 101, and a second distance is set between the second optical component 204 and the second waveguide 201 to the extent that the desired relative position and orientation of the first and second optical component, 100 and 200, is thereby set in the normal direction and thus also the waveguides, 101 and 201, are aligned with respect to one another in the normal direction to the extent that the optical coupling thereof is enabled.

(49) Because the waveguides, 101 and 201, are thus precisely aligned both laterally and also normally with respect to one another, an optical coupling of the waveguides, 101 and 201, is established.

(50) FIG. 7b to FIG. 7e show the system 400 after various optional further method steps, with which the optical system 400 can be further processed.

(51) As shown in FIG. 7b, a sacrificial structure 402 can be attached to the back side 105 of the first optical component 100 in this case. A sub-carrier 403 with a recess 410 for accommodating the carrier substrate 300 can be attached to the front side 204 of the second optical component.

(52) In addition, as shown in FIGS. 7c and 7d, wherein FIG. 7d is a detailed view of the region marked by an ellipse in FIG. 7c, any remaining gaps between the waveguides, 101 and 201, can be filled with an optical filling material 404. The optical filling material 404 in this case has properties beneficial for the optical coupling (wavelength transmission, refractive index, dispersion function, etc.).

(53) Subsequently, gaps remaining between the optical components, 100 and 200, can be filled with a potting compound 405. The carrier substrate 300 and/or the sub-carrier 403 can be removed, for example, by means of laser debonding or grinding. The (cured) potting compound 405, the silicon layer 203, and the sacrificial structure 402 can be thinned by grinding down to a common back side 406.

(54) As shown in FIG. 7e, the optical components, 100 and 200, can be electrically contacted with thin-film multilayer wiring 408 and provided with bumps (contact elements) 409 on an exposed common front side 407.

(55) Of course, the number, type, and sequence of the steps of the method can be adapted, as is directly clear to one skilled in the art (particularly with respect to the optical system to be produced and/or the properties of the optical components used).

LIST OF REFERENCE NUMERALS

(56) 100 First optical component

(57) 101 First waveguide

(58) 102 First substrate layer

(59) 103 Second substrate layer

(60) 104 Front side

(61) 105 Rear side

(62) 109 End face

(63) 110 First markup set

(64) 200 Second optical component

(65) 201 Second waveguide

(66) 202 SiO2 layer

(67) 203 Silicon layer

(68) 204 Front side

(69) 205 Rear side

(70) 206 Recess

(71) 209 End face

(72) 210 Second markup set

(73) 220 Mask

(74) 221 Trenches

(75) 222 Core

(76) 300 Carrier substrate

(77) 301 Adhesive layer

(78) 302 Adhesive structures

(79) 304 Front side

(80) 305 Rear side

(81) 310 Second markup set

(82) 311 Metal layer

(83) 320 Polymer layer

(84) 321 Carrier substrate waveguide

(85) 400 Optical system

(86) 402 Sacrificial structure

(87) 403 Auxiliary carrier

(88) 404 Optical filler material

(89) 405 Casting compound

(90) 406 Rear side

(91) 407 Front side

(92) 408 Thin film multilayer wiring

(93) 409 Bumps

(94) 410 Recess

(95) 500 Carrier

(96) 600 Flip chip bonder

(97) 601 Chuck

(98) 602 Bond arm

(99) 603 Flip arm

(100) 604 Camera system