Bendable carrier mount, device and method for releasing a carrier substrate

Abstract

A flexible carrier mount for mounting of a carrier substrate when the carrier substrate is detached from a product substrate, detachment means being provided for debonding the product substrate with bending of the carrier substrate. A device for detaching a carrier substrate from one product substrate in one detachment direction having: a carrier mount flexible in the detachment direction for mounting the carrier substrate, a substrate mount for mounting the product substrate, and detachment means for debonding the carrier substrate from the product substrate with bending of the carrier substrate. A method for detaching a carrier substrate from a product substrate in one detachment direction with the steps: mounting the product substrate with a substrate mount and mounting the carrier substrate with a carrier mount flexible in the detachment direction and debonding the carrier substrate from the product substrate with bending of the carrier substrate.

Claims

1. A system for debonding a product substrate from a carrier substrate, the product substrate being temporarily connected to the carrier substrate by an interconnect layer to form a stack, the system comprising: means configured to support the stack; separating means comprising a compressed air jet configured to provide an air flow to initiate separation of the product substrate from the carrier substrate and penetrate locally into the interconnect layer of the stack from a peripheral edge of the interconnect layer; a first member having a surface extending in a plane generally parallel to a plane of a surface of the carrier substrate; and an extension portion extending from the first member, the extension portion including a surface configured to contact a peripheral edge of the carrier substrate, wherein the system applies a force to the carrier substrate to bend the carrier substrate away from the product substrate and thereby debond the product substrate from the carrier substrate at a migrating detachment front, wherein the separating means are independent of the extension portion and configured to act locally on the detachment front, and wherein the air flow is heated to locally heat the detachment front to initiate separation of the carrier substrate from the product substrate.

2. The system as claimed in claim 1, wherein said first member is flexible.

3. The system as claimed in claim 1, wherein one end of the surface of the extension portion terminates at an inner edge configured to contact the peripheral edge of the carrier substrate.

4. A system for debonding a carrier substrate from a product substrate, the carrier substrate being temporarily connected to the product substrate by an interconnect layer to form a stack, the system comprising: a first mount engageable with the carrier substrate, the first mount including: a shoulder having a shoulder surface extending in a plane generally parallel to a surface of the carrier substrate that is in contact with the interconnect layer; and an extension portion extending from the shoulder, the extension portion having an inner edge forming a tip that is configured to contact a peripheral edge of the carrier substrate and initiate a debonding process whereby the carrier substrate is separated from the product substrate; and separating means comprising a compressed air jet configured to provide an air flow to initiate separation of the carrier substrate from the product substrate and penetrate locally into the interconnect layer of the stack from a peripheral edge of the interconnect layer, wherein the first mount applies a force to the carrier substrate to bend the carrier substrate away from the product substrate and thereby debond the carrier substrate from the product substrate, said carrier substrate debonding from the product substrate beginning at a periphery of the carrier substrate at a migrating detachment front, wherein the separating means are independent of the extension portion and configured to act locally on the detachment front, and wherein the air flow is heated to locally heat the detachment front to initiate separation of the carrier substrate from the product substrate.

5. The system as claimed in claim 4, wherein said first mount is flexible.

6. The system as claimed in claim 4, further comprising: first drive means configured to move the first mount in order to apply the force to the carrier substrate to bend the carrier substrate away from the product substrate.

7. The system as claimed in claim 4, further comprising: a second mount engageable with the product substrate.

8. The system as claimed in claim 7, further comprising: first drive means configured to move the first mount in order to apply the force to the carrier substrate to bend the carrier substrate away from the product substrate; and second drive means configured to move said second mount relative to said first mount.

9. A system for debonding a product substrate from a carrier substrate, the product substrate being temporarily connected to the carrier substrate by an interconnect layer to form a stack, the system comprising: means configured to support the stack; separating means comprising a compressed air jet configured to provide an air flow to initiate separation of the product substrate from the carrier substrate and penetrate locally into the interconnect layer of the stack from a peripheral edge of the interconnect layer; a first member having a surface extending in a plane generally parallel to a plane of a surface of the carrier substrate; and an extension portion extending from the first member, the extension portion including a surface configured to contact a peripheral edge of the carrier substrate, wherein the system applies a force to the carrier substrate to bend the carrier substrate away from the product substrate and thereby debond the product substrate from the carrier substrate at a migrating detachment front, wherein the separating means are independent of the extension portion and configured to act locally on the detachment front, and wherein the separating means comprise a separating wire that is configured to act locally on the detachment front in a tensioned state along a plane in which the detachment front resides to initiate separation of the carrier substrate from the product substrate.

10. A system for debonding a product substrate from a carrier substrate, the product substrate being temporarily connected to the carrier substrate by an interconnect layer to form a stack, the system comprising: means configured to support the stack; separating means comprising a compressed air jet configured to provide an air flow to initiate separation of the product substrate from the carrier substrate and penetrate locally into the interconnect layer of the stack from a peripheral edge of the interconnect layer; a first member having a surface extending in a plane generally parallel to a plane of a surface of the carrier substrate; and an extension portion extending from the first member, the extension portion including a surface configured to contact a peripheral edge of the carrier substrate, wherein the system applies a force to the carrier substrate to bend the carrier substrate away from the product substrate and thereby debond the product substrate from the carrier substrate at a migrating detachment front, wherein the separating means are independent of the extension portion and configured to act locally on the detachment front, and wherein the separating means comprise a separating blade, the separating blade having a sharp edge configured to act locally on the detachment front to initiate separation of the carrier substrate from the product substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a plan view of one carrier mount according to the present invention with a cutting line A-A,

(2) FIG. 2 shows a cross sectional view of the carrier mount according to cutting line A-A from FIG. 1,

(3) FIG. 3 shows a view of the carrier mount according to FIG. 1 from underneath,

(4) FIG. 4 shows a detailed view of detail E from FIG. 2,

(5) FIG. 5a shows a side view of a stack composed of the carrier substrate, interconnect layer and product substrate,

(6) FIG. 5b shows a plan view of a stack composed of the carrier substrate, interconnect layer and product substrate,

(7) FIG. 6 shows a detailed view analogously to FIG. 4 with a first embodiment of the carrier mount,

(8) FIG. 7 shows a detailed view analogously to FIG. 4 with a second embodiment of the carrier mount,

(9) FIG. 8 shows a stack fixed on a film frame,

(10) FIGS. 9a-9d show a first embodiment of the device with four method steps and

(11) FIGS. 10a-10d show a second embodiment of the device with four method steps.

(12) The same components or components with the same function are identified with the same reference numbers in the figures.

DETAILED DESCRIPTION OF THE INVENTION

(13) FIG. 1 shows a carrier mount 1 which can be used semiautomatically, and in which the carrier substrate 13 is held manually by the carrier mount 1. The carrier mount 1 is used for debonding the carrier substrate 13 from a product substrate 11 which is connected to the carrier substrate by an interconnect layer 12.

(14) The carrier mount 1 consists of a holding handle 2 which is located on one peripheral section 26 and of a ring 3 which is opened opposite the holding handle 2. On the opening 3o of the ring 3 there are spacing means 25 for adjustment of the spacing A between the ends 24, 24 on the opposite ends 24, 24 of the ring 3. An inside diameter D.sub.i and an outside diameter D.sub.a of the ring 3 can be adjusted by adjusting the spacing A. The spacing means 25 in this exemplary embodiment consist of levers 4, 5, the lever 4 being attached on the end 24 and the lever 5 on the end 24. The levers 4, 5 are penetrated by positioning elements 14 which can be operated manually here. Automatic re-positioning of the above described manual kinematics is conceivable.

(15) The holding handle 2 is attached to the ring 3 by fixing elements 10, especially screws. The material of the ring 3 for a given geometry (ring height H, ring width B, outside diameter D.sub.a, inside diameter D.sub.i) should be chosen such that the ring 3 can be elastically bent by the spacing means 25 against its force caused by the bending stiffness.

(16) The ring 3 has a peripheral shoulder 7 which projects away from a ring shoulder 6, and a step 9. The step 9 runs in a z-shape with an inside angle 45<I<90, especially <80, preferably <70 pointed toward the middle of the ring and thus forms an especially peripherally running wall bevel 17 which ends on a sharp inner edge 8. The inner edge 8 is at the same time a component of a face surface 7s of the peripheral shoulder 7, which surface runs parallel to the ring shoulder 6. The face surface 7s is equidistant to the ring shoulder 6 with a distance M. The distance M is chosen such that it is at most slightly larger, especially at most larger by the thickness of the interconnect layer 12, than one thickness d of the carrier substrate 13 (see FIG. 7). Preferably the distance M is chosen as shown in FIG. 6 such that it is smaller than the thickness d of the carrier substrate 13. Preferably the distance M is at least half as great as the thickness d of the carrier substrate 13.

(17) A diameter D.sub.k which lies between the inside diameter D.sub.i and the outside diameter D.sub.a for holding the carrier substrate 13 and which is formed by the inner edge 8 can be increased by the spacing means 25 until the carrier substrate 13 can be inserted through an opening (diameter D.sub.k) formed by the inner edge 8 as far as the ring shoulder 6. Then the diameter D.sub.k can be again reduced by the spacing means 25 until one peripheral edge 13u of the carrier substrate 13 adjoins the bevel 17 of the peripheral shoulder 7 and is fixed by it. Thus the carrier substrate 13 is held by the flexible carrier mount 1. The mounting takes place more or less by clamping and/or by form fit. For clamping of the carrier substrate 13 on the bevel 17 there can be dynamometer means for control of the clamping, especially on the positioning means 14.

(18) The product substrate 11 is only attached to the carrier mount 1 via the interconnect layer 12. There is no direct contact between the carrier mount 1 and the product substrate 11. While avoiding contact between the carrier mount 1 and the product substrate 11 the product substrate 11 is protected to the maximum degree and contamination or damage is essentially precluded.

(19) The product substrate 11 with the interconnect layer 12 and the carrier substrate 13 forms a stack 19 (carrier substrateproduct substratecombination). This invention is likewise suited for a combination of carrier substrate and product substrate without interposed interconnect layer, especially for so-called prebonds, in which the wafers adhere to one another especially by means of Van der Waals forces.

(20) When fixing the stack 19 on the carrier mount 1 in the embodiment shown in FIG. 7 the sharp inner edge 8 is used at the same time as a separating means or to initiate debonding by the tip of the inner edge 8 on the peripheral edge of the interconnect layer 12 penetrating into the interconnect layer 12.

(21) The carrier mount 1 almost completely surrounds the carrier substrate 13, except for the ring opening 3o.

(22) FIG. 8 shows the stack 19 on a film frame 23, the product substrate 11 being connected to a film 21 which is joined to the film frame 23. The stack 19, the film frame 23 and the film 21 form a film frame combination 20.

(23) The carrier substrate 13 can be pulled off the product substrate 11 by means of the holding handle 2 and by fixing of the product substrate 11 or of the film frame 23. The tensile force is applied laterally to the carrier substrate 13, therefore to the peripheral section 26 by the unilateral arrangement of the holding handle 2. Initiated by the penetration of the inner edge 8 into the interconnect layer 12, the carrier substrate 13 with deformation of the carrier substrate 13 and of the ring 3 (against its force produced by the bending stiffness) is slowly debonded proceeding from the peripheral section 26 to the opposite side. Here a detachment front migrates from the peripheral section 26 to the opposite side of the carrier substrate 13 by the interconnect layer 12. Accordingly, depending on the distance of the detachment front from the holding handle 2 and the detachment force applied to the holding handle 2, defined torques act along the detachment front.

(24) In automated form this is shown in FIGS. 9a to 9d in a first embodiment and in FIGS. 10a to 10d in a second embodiment, which are detailed below.

(25) The use of the above described carrier mount 1 for mounting of the carrier substrate 13 in a form suitable for automation is common to the two embodiments.

(26) One important aspect of the invention consists in providing especially careful handling at the start of debonding, therefore when debonding is initiated, especially by implementation of a mechanical debonding of the interconnect layer on the periphery or on its edge.

(27) FIGS. 9 and 10 each show one base 27 and one rack 22 which is mounted on it for providing a stable base construction and for attachment of other components of the device, which are described below. On the rack 22 or the base 27, especially between a cover 22d of the rack 22 and a bottom 27b formed by the base 27, there are drive means 15 for translational movement (especially driven) of the carrier mount 1 or of peripheral sections of the carrier mount 1 and drive means 15 for translational movement (especially driven) of a substrate mount 18 (receiver) which holds the stack 19 or the film frame combination 20. The drive means 15 can have a trip-free mechanism in the direction of translation, especially formed by a movable bearing.

(28) The substrate mount 18 in the two embodiments as shown in FIG. 9 and FIG. 10 can be moved up and/or down in translation in one detachment direction L, therefore in the plane of the drawing. The drive means 15 for driving the substrate mount 18 can thus be moved especially synchronously, preferably driven by motors, especially stepping motors, which are controlled by a central control device.

(29) In the embodiment as shown in FIG. 9, for the carrier mount 1 there is only one drive means 15 on the side of the carrier mount 1 opposite the peripheral section 26, while on the peripheral section 26 there is one rocker bearing 16, so that the carrier mount can be pivoted around the rocker bearing 16, but is fixed in the detachment direction L. Thus the sequence of the method is as follows:

(30) In the method step shown in FIG. 9a, the carrier mount 1 which is suitable for the film frame combination 20, especially the carrier substrate 13, is attached to the upper drive means 15 and the rocker bearing 16. At the same time, beforehand or subsequently, the film frame combination 20 is fixed onto the substrate mount 18, in particular by application of a vacuum. The substrate mount 18 can be moved by the drive means 15 in the detachment direction L.

(31) It is alternatively conceivable that on the periphery of the carrier mount 1 there are several, especially two, drive means 15 on one side and several, especially two, rocker bearings 16 on the opposite side.

(32) The carrier mount 1 can be fixed by holding means 28 which are located on the ring periphery 3u on the drive means 15 and the rocker bearing 16. The substrate mount 18 can be fixed by holding means 29 on the drive means 15.

(33) Then the substrate mount 18 is moved into the position shown in FIG. 9b (therefore in the detachment direction L toward the carrier mount 1) by the drive means 15 executing a synchronous translational movement of the substrate mount 18 until the carrier substrate 13 with its top 13o adjoins the ring shoulder 6. Control can take place via the central control device, the detection of the carrier substrate 13 striking the ring shoulder 6 taking place by force transducers which are integrated especially into the substrate mount 18. Preferably on the periphery of the substrate mount 18 there are a number n of force transducers distributed at an angular distance of 360/n.

(34) So that the carrier substrate 13 can be held in the carrier mount 1, the diameter D.sub.k must be matched accordingly beforehand to the inner edge 8 of the ring 3 so that the carrier substrate 13 with its outside contour (especially circular with a diameter D.sub.t) can be received into the carrier mount 1. When the carrier mount 13 is received the inside diameter D.sub.i is smaller than the diameter D.sub.t of the carrier substrate 13 so that the carrier substrate 13 does not slip through. As soon as the position shown in FIG. 9b is reached, the inside diameter D.sub.i can be reduced until the carrier substrate 13 is fixed in the carrier mount 1 (see FIGS. 6 and 7), and therefore adjoins the wall bevel 17.

(35) As soon as the position which is shown in FIG. 9b is reached, the upper fixable drive means 15 is released so that it has a degree of freedom in the detachment direction L and the side of the carrier mount 1 attached to the drive means 15 can move freely in the detachment direction L. In this embodiment the drive means 15 is made driveless. But a control of the motion by the central device is also conceivable so that the drive means 15 is made not passive (as in the preferred embodiment), but active.

(36) Then, on the two drive means 15 which are provided opposite on the substrate mount 18 one drive force F.sub.1 (tensile force) which is pointed away from the carrier mount 1 and one drive force F.sub.2 (tensile force) which is especially identical to the drive force F.sub.1 are applied especially synchronously to the substrate mount 18 for debonding of the carrier substrate 13 which is fixed on the carrier mount 1 from the product substrate 11.

(37) Acting opposite the drive forces F.sub.1 and F.sub.2 and especially parallel to them, an opposing force G (or several opposing forces G, if there are several rocker bearings 16) is applied to the rocker bearing 16.

(38) In this way the debonding process which has been initiated from the inner edge 8 is continued, with increasing bending of the carrier mount 1 and of the carrier substrate 13 a detachment front running from the rocker bearing 16 to the opposite side of the carrier mount 1. In equilibrium with the drive forces F.sub.1 and F.sub.2 as well as the opposing force G (caused by the interconnecting force of the interconnect layer 12), torques act along the detachment front as detachment moments K.sub.1 to K.sub.n which are distributed infinitesimally along the detachment front.

(39) In the position shown in FIG. 9c, the carrier substrate 13 is debonded by more than half, debonding taking place by both the carrier substrate 13 and also the carrier mount 1 deforming (against the bending strength of the carrier mount 1 and of the carrier substrate 13).

(40) In the position shown in FIG. 9d, the carrier substrate 13 is debonded completely from the product substrate 11. The interconnect layer 12 in the figure adheres to the product substrate 11, but can also adhere partially or completely to the carrier substrate 13.

(41) During the debonding, the carrier mount 1 and the carrier substrate 13 bend by an (average, especially measured at half debonding of the carrier substrate 13 from the product substrate 11) bending angle 1<W<45, especially W<35, here roughly 6.

(42) In the second embodiment as shown in FIG. 10a to FIG. 10d, instead of the drive means 15 there is a rocker bearing 16 on the carrier mount 1 so that the carrier mount 1 on the peripheral sections 26 and an opposite peripheral section 26 (therefore where the rocker bearings 16 are attached to holding means 28 of the carrier mount 1) is fixed in the detachment direction L (there can be several rocker bearings 16 on the periphery of the carrier mount 1). In sections between the peripheral sections 26 the carrier mount 1 is movable within the framework of its flexibility against the bending stiffness. Thus when the drive forces are applied in the method step according to 10c, a detachment front which runs essentially (rippled) concentrically from the periphery of the interconnect layer 12 arises to the middle of the interconnect layer 12. Here the initiation by the inner edge 8 of the carrier mount plays an important part for overcoming the initial interconnecting force of the interconnect layer 12.

(43) The detachment moments K.sub.1 to K.sub.n act in the embodiment as shown in FIGS. 10a to 10d each predominantly on one (rippled) circular section along the detachment front as the detachment front progresses. While the bending angle W according to FIG. 9c to the side edge opposite the rocker bearing is measured, the bending angle W is measured from the center of the carrier substrate 13 to the edge due to the detachment force K which acts on the periphery from all sides, the bending angle W in this case being correspondingly smaller due to the shorter distance, insofar as the material of the carrier mount 1 and of the carrier substrate 2 as well as their dimensions are otherwise identical. By reducing the ring width B and/or the ring height H the bending stiffness of the ring 3 can be reduced so that the bending angle W would be increased.

REFERENCE NUMBER LIST

(44) 1 carrier mount 2 holding handle 3 ring 3o opening 3u ring periphery 4 lever 5 lever 6 ring shoulder 7 peripheral shoulder 7s face surface 8 inner edge 9 step 10 fixing means 11 product substrate 12 interconnect layer 13 carrier substrate 13o top 13u peripheral edge 14 positioning elements 15, 15 drive means 16 rocker bearing 17 bevel 18 substrate mount 19 stack 20 film frame combination 21 foil 22 rack 22d cover 23 film frame 24, 24 ends 25 spacing means 26 peripheral section 27 base 27b bottom 28 holding means 29 holding means A spacing B ring width D.sub.i inside diameter D.sub.a outside diameter D.sub.k diameter H ring height M distance L detachment direction I inner angle d thickness F.sub.1, F.sub.2, F.sub.n drive forces (tensile force) G opposing force K.sub.1, K.sub.2, K.sub.n detachment moments W, W bending angles