Method for iii-v/silicon hybrid integration

Abstract

A method of transfer printing. The method comprising: providing a precursor photonic device, comprising a substrate and a bonding region, wherein the precursor photonic device includes one or more alignment marks located in or adjacent to the bonding region; providing a transfer die, said transfer die including one or more alignment marks; aligning the one or more alignment marks of the precursor photonic device with the one or more alignment marks of the transfer die; and bonding at least a part of the transfer die to the bonding region.

1 . A method of transfer printing, comprising:
 providing a precursor photonic device, comprising a substrate and a bonding region, wherein the precursor photonic device includes one or more alignment marks located in or adjacent to the bonding region;   providing a transfer die, said transfer die including one or more alignment marks;   aligning the one or more alignment marks of the precursor photonic device with the one or more alignment marks of the transfer die; and   bonding at least a part of the transfer die to the bonding region.   
     
     
         2 . The method of  claim 1 , wherein the precursor photonic device, or the transfer die, or both, include one or more metal patches covering the respective alignment marks. 
     
     
         3 . The method of  claim 2 , wherein the at least one or more alignment marks located in or adjacent to the bonding region or the at least one of the one or more alignment marks included in the transfer die, or both, include one or more trenches etched to surround the alignment marks and covered by the metal patch. 
     
     
         4 . The method of any preceding claim, wherein the precursor photonic device includes a first waveguide and the transfer die includes a second waveguide, and, once bonded, an interface between the first waveguide and the second waveguide is angled relative to a guiding direction of the first waveguide or second waveguide. 
     
     
         5 . The method of  claim 4 , wherein the first waveguide, the second waveguide, or both, include a T-bar facet. 
     
     
         6 . The method of any preceding claim, wherein at least one of the one or more alignment marks located in or adjacent to the bonding region or at least one of the one or more alignment marks included in the transfer die, or both, are formed in one of the following shapes: a rectangle, a square, an L-shape, a circle, a ring, a partial circle, and a partial ring. 
     
     
         7 . The method of any preceding claim, wherein the precursor photonic device includes one more alignment marks located adjacent to the bonding region, and once bonded, a closest distance between one of the one or more alignment marks adjacent to the bonding region and a corresponding one of the one or more alignment marks included in the transfer die is at least 50 μm and no more than 1000 μm. 
     
     
         8 . The method of any preceding claim, wherein the or each alignment mark located in or adjacent to the bonding region is symmetrical as compared to a corresponding alignment mark included in the transfer die. 
     
     
         9 . The method of any preceding claim, wherein the precursor photonic device is as set out in any of  claims 22 - 33 . 
     
     
         10 . The method of any preceding claim, wherein the transfer die is as set out in any of  claims 21 - 32 . 
     
     
         11 . The method of any preceding claim, further comprising a step of filling a facet between the precursor photonic device and the transfer die. 
     
     
         12 . The method of  claim 11 , wherein the filling material used to fill the facet is silicon nitride, amorphous silicon, a dielectric, or a benzocyclobutene resin. 
     
     
         13 . The method of any preceding claim, further comprising one or more steps of:
 plasma treating the precursor photonic device and/or the transfer die;   dipping the precursor photonic device in water;   drying the precursor photonic device; and   annealing the transfer die and precursor photonic device.   
     
     
         14 . The method of  claim 13 , wherein the annealing is performed at a temperature of at least 250° C. and no more than 350° C. for a time of at least 20 minutes and no more than 400 minutes. 
     
     
         15 . The method of  claim 14 , wherein the annealing is performed in an inert gas atmosphere, such as nitrogen atmosphere or argon atmosphere. 
     
     
         16 . An optoelectronic device, produced using the method of any of  claims 1 - 15 . 
     
     
         17 . An optoelectronic device, comprising:
 a silicon-on-insulator wafer, having a cavity; and   a III-V semiconductor based photonic device, located within and bonded to the cavity;   wherein the III-V semiconductor based photonic device includes one or more alignment marks, which align with corresponding alignment mark(s) on the silicon-on-insulator wafer.   
     
     
         18 . The optoelectronic device of  claim 17 , wherein the one or more alignment marks are located in an optically transparent region of the III-V semiconductor based photonic device. 
     
     
         19 . The optoelectronic device of  claim 17 , wherein the one or more alignment marks are voids in the III-V semiconductor based photonic device that extend entirely through the III-V semiconductor based photonic device. 
     
     
         20 . The optoelectronic device of any of  claims 17  to  19 , further comprising an input and/or output waveguide, the waveguide(s) being provided in the silicon-on-insulator wafer and optically coupled to the III-V semiconductor based photonic device. 
     
     
         21 . An optoelectronic device comprising:
 the precursor photonic device of any of  claims 22 - 33 , bonded to the transfer die of any of  claims 34 - 46 .   
     
     
         22 . A precursor photonic device, comprising:
 a substrate;   a bonding region, for receiving and bonding to a transfer die; and   one or more alignment marks, for use in transfer printing, said alignment marks being located in or adjacent to the bonding region.   
     
     
         23 . The precursor photonic device of  claim 22 , wherein the bonding region is in a cavity, provided in the substrate. 
     
     
         24 . The precursor photonic device of either of  claim 22  or  23 , further comprising an input waveguide, wherein the alignment marks are configured to align a photonic device, located on the transfer die, relative to the input waveguide. 
     
     
         25 . The precursor photonic device of any of  claims 22 - 24 , wherein the one or more alignment marks allow for alignment in at least two non-parallel directions. 
     
     
         26 . The precursor photonic device of any of  claims 22 - 25 , wherein the one or more alignment marks are provided as one or more etched regions and/or as one or more patterned metal surfaces. 
     
     
         27 . The precursor photonic device of  claim 26 , wherein the etched regions have a depth of at least 100 nm and no more than 3000 nm. 
     
     
         28 . The precursor photonic device of any of  claims 22 - 27 , including one or more coarse alignment marks, and one or more fine alignment marks. 
     
     
         29 . The precursor photonic device of  claim 28 , wherein the one or more coarse alignment mark(s) project in at least two non-parallel directions 
     
     
         30 . The precursor photonic device of either  claim 28  or  claim 29 , wherein the one or more coarse alignment mark(s) are shaped as any one or more of: an arrow, a cross, a T shape, and an L shape. 
     
     
         31 . The precursor photonic device of any of  claims 28 - 30 , wherein there are two or more fine alignment marks which respectively project in at least two non-parallel directions 
     
     
         32 . The precursor photonic device of any of  claims 28 - 31 , wherein the one or more fine alignment mark(s) include Vernier patterns. 
     
     
         33 . The precursor photonic device of any of  claims 22 - 32 , wherein the precursor photonic device is a silicon-on-insulator wafer, including either or both of an input waveguide and an output waveguide, each adjacent to the bonding region. 
     
     
         34 . A transfer die comprising:
 a photonic device, said photonic device having a bonding surface suitable for bonding to a precursor photonic device;   wherein the transfer die includes one or more alignment marks, for use in a transfer-print process.   
     
     
         35 . The transfer die of  claim 34 , wherein the photonic device is a III-V semiconductor device and/or the transfer die includes a sacrificial layer. 
     
     
         36 . The transfer die of either  claim 34  or  claim 35 , wherein the photonic device is a laser, semiconductor optical amplifier, or an electro-absorption modulator. 
     
     
         37 . The transfer die of  claim 36 , wherein the photonic device is an electro-absorption modulator, wherein said electro-absorption modulator comprises an input waveguide and an output waveguide, and wherein both of said input waveguide and said output waveguide comprise a port located on a same side of the transfer die. 
     
     
         38 . The transfer die of any of  claims 34 - 37 , wherein the photonic device is formed at least partially from indium phosphide, and/or a sacrificial layer is formed of indium gallium arsenide. 
     
     
         39 . The transfer die of any of  claims 34 - 38 , wherein the alignment marks are provided on an optically transparent region of the transfer die. 
     
     
         40 . The transfer die of any of  claims 34 - 38 , wherein the alignment marks are voids in the transfer die which extend entirely through the transfer die. 
     
     
         41 . The transfer die of any of  claims 34 - 40 , formed on an indium phosphide substrate. 
     
     
         42 . The transfer die of any of  claims 34 - 41 , wherein the photonic device includes one or more coarse alignment marks and one or more fine alignment marks. 
     
     
         43 . The transfer die of  claim 42 , wherein the one or more coarse alignment mark(s) project in at least two non-parallel directions. 
     
     
         44 . The transfer die of either of  claim 42  or  43 , wherein the one or more coarse alignment mark(s) are shaped as any one or more of: an arrow, a cross, a “T” shape, and an “L” shape. 
     
     
         45 . The transfer die of any of  claims 42 - 44 , wherein there are two or more fine alignment marks which respectively project in at least two non-parallel directions. 
     
     
         46 . The transfer die of any of  claims 42 - 45 , wherein the one or more fine alignment mark(s) include Vernier patterns. 
     
     
         47 . A platform wafer, suitable for use in a transfer printing process, said platform wafer including:
 one or more alignment chips, said alignment chips including one or more alignment marks; and   one or more precursor photonic device(s).   
     
     
         48 . The platform wafer of  claim 37 , wherein the precursor photonic device is as set out in any of  claims 22 - 33 . 
     
     
         49 . A transfer wafer, suitable for use in a transfer printing process, said wafer including:
 one or more alignment chips, said alignment chips including one or more alignment marks; and   one or more device chips.   
     
     
         50 . The transfer wafer of  claim 49 , wherein the transfer wafer includes one or more transfer dies as set out in any of  claims 34 - 46 . 
     
     
         51 . A method of preparing a precursor photonic device, comprising the steps of:
 providing a wafer, comprising a substrate and a device layer; and   etching one or more alignment marks into the wafer.   
     
     
         52 . The method of  claim 51 , further comprising:
 etching a cavity into the wafer, said cavity extending from an uppermost surface of the device layer to at least an uppermost surface of the substrate; and   etching the one or more alignment marks into the substrate.   
     
     
         53 . The method of either of  claim 51  or  52 , further comprising a step of etching at least one of an input waveguide and an output waveguide, said input waveguide and/or output waveguide having a surface adjacent to the cavity. 
     
     
         54 . The method of  claim 53 , wherein the step of etching the one or more alignment marks is performed at the same time as etching the input waveguide and/or output waveguide. 
     
     
         55 . The method of  claim 54 , wherein the step of etching the one or more alignment marks and the input waveguide and/or output waveguide comprises the sub-steps of:
 (a) providing a photoresist over an upper surface of the precursor photonic device;   (b) patterning the photoresist to provide one or more exposed regions; and   (c) etching the exposed regions.   
     
     
         56 . The method of any of  claims 51 - 55 , further comprising a step of depositing an antireflective coating, preferably formed of silicon nitride, along either or both of: one or more sidewalls; and/or a bed of the cavity. 
     
     
         57 . The method of  claim 56 , further comprising a step of removing at least the antireflective coating present adjacent to the alignment marks. 
     
     
         58 . The method of any of  claims 51 - 57 , further comprising a step of depositing a top cladding layer over the exposed upper surface of the precursor photonic device, after the step of etching the one or more alignment marks. 
     
     
         59 . The method of  claim 58 , comprising a step of removing portions of the top cladding layer which are within the cavity. 
     
     
         60 . A method of forming a transfer die, comprising the steps of:
 providing a multi-layered structure, said multi-layered structure including at least a sacrificial layer and one optically active layer; and   etching one or more alignment marks into a part of the multi-layered structure.   
     
     
         61 . The method of  claim 60 , wherein the step of etching one or more alignment marks is performed concurrently with a step of etching one or more device structures into the multi-layered structure. 
     
     
         62 . The method of  claim 60 , further includes a step of depositing a stress compensation layer. 
     
     
         63 . The method of any of  claims 60 - 62 , wherein etching one or more alignment marks into a part of the multi-layered structure includes etching a region of the transfer die such that it is optically transparent. 
     
     
         64 . The method of any of  claims 60 - 63 , wherein the alignment marks are etched entirely through the multi-layered structure.