# US 8,541,294 B2 · Method of forming epitaxial film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,294 B2 - Document ID: US8541294B2 - Status: Granted - Kind: B2 - Application number: 13/487,592 - Filed: 2012-06-04 - Published: 2012-09-20 - Granted: 2013-09-24 - Earliest claimed: 2008-10-28 - Assignees: Athenaeum, LLC - Applicants: Eric Ting-Shan Pan - Inventors: Eric Ting-Shan Pan - Web page: https://patentgrep.com/patent/US8541294B2 ## CPC - C30B 35/00: Apparatus not otherwise provided for, specially adapted for the growth, production or after-treatment of single crystals or of a homogeneous polycrystalline material with defined structure - C30B 11/002: {Crucibles or containers for supporting the melt} - C30B 11/14: characterised by the seed, e.g. its crystallographic orientation - C30B 19/06: Reaction chambers; Boats for supporting the melt; Substrate holders - C30B 19/12: characterised by the substrate - H10F 10/161: comprising multiple PN heterojunctions, e.g. tandem cells - H10F 10/163: comprising only Group III-V materials, e.g. GaAs/AlGaAs or InP/GaInAs photovoltaic cells - H10F 71/1272: {comprising at least three elements, e.g. GaAlAs or InGaAsP} - H10P 14/263: {using melted materials} - Y02E 10/544: Solar cells from Group III-V materials - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method of growing an epitaxial film and transferring it to an assembly substrate is disclosed. The film growth and transfer are made using an epitaxy lateral overgrowth technique. The formed epitaxial film on an assembly substrate can be further processed to form devices such as solar cell, light emitting diode, and other devices and assembled into higher integration of desired applications. ## Claims ### Claim 1 A method of forming an epitaxial thin film comprising: melting a liquid phase epitaxial material within a pocket; directing said liquid phase epitaxial material onto an assembly substrate using a manifold; retaining said assembly substrate with a first frame portion; wherein said assembly substrate includes a plurality of openings; retaining a seed substrate adjacent to said assembly substrate such that said liquid phase material is introduced into a template within said assembly substrate and contacts a surface of said seed substrate through said plurality of openings; controlling melting and cooling of said liquid phase epitaxial material within said assembly substrate so as to form an epitaxial layer; controlling a temperature of said liquid phase epitaxial material while or before moving said first frame portion and/or a second base portion so as to separate said epitaxial layer from said seed substrate; wherein said epitaxial layer can be transferred as a distinct layer from said seed substrate. ### Claim 2 (depends on 1) The method of claim 1, wherein said epitaxial layer can be grown laterally across a top surface of said assembly substrate. ### Claim 3 (depends on 1) The method of claim 1, further including a step: processing said assembly substrate and epitaxial layer as an integrated epitaxial packaged structure within a semiconductor processing apparatus to form active devices on said assembly substrate and/or said epitaxial layer. ### Claim 4 (depends on 1) The method of claim 1 wherein said epitaxial layer includes a graded composition throughout a thickness direction of said assembly substrate. ### Claim 5 (depends on 1) The method of claim 1 wherein said liquid phase epitaxial material is adapted with thermal characteristics matching said assembly substrate. ### Claim 6 (depends on 1) The method of claim 1, wherein said separating is achieved at least in part by a shearing action. ### Claim 7 (depends on 1) The method of claim 1, wherein said separating is achieved at least in part by a chemical etchant. ### Claim 8 (depends on 1) The method of claim 1 further including a step: forming one or more second separate thin film epitaxial layers on said epitaxial layer. ### Claim 9 (depends on 8) The method of claim 8 wherein said one or more second separate thin film epitaxial layers and said thin film epitaxial layer include different dopant species. ### Claim 10 (depends on 1) The method of claim 1 further including a step: forming one or more second separate assembly substrates on said epitaxial layer. ### Claim 11 (depends on 1) The method of claim 1 wherein said epitaxial layer has a multidimensional structure including lines and via interconnects. ### Claim 12 (depends on 1) The method of claim 1, wherein said epitaxial layer forms part of a p-n junction. ### Claim 13 (depends on 1) The method of claim 1, wherein said epitaxial layer forms part of an integrated circuit device. ### Claim 14 (depends on 1) The method of claim 1 further including a step of forming a sacrificial layer attached between a bottom surface of said assembly substrate and a surface of a crystalline substrate. ### Claim 15 (depends on 14) The method of claim 14 further including a step of forming a spacer situated adjacent said assembly substrate and above said crystalline substrate. ### Claim 16 (depends on 14) The method of claim 14 wherein said crystalline substrate can be re-used for growing a second epitaxial layer with said assembly substrate after said epitaxial layer is separated. ### Claim 17 (depends on 1) The method of claim 1 further including a step: controlling heating and cooling of said liquid phase epitaxial material. ### Claim 18 (depends on 1) The method of claim 1 further including a step: controlling a side profile of said openings to be vertical, step recessed or sloped to any desired angle. ### Claim 19 A method of forming an epitaxial thin film comprising: melting a liquid phase epitaxial material within a pocket; directing said liquid phase epitaxial material onto an assembly substrate using a manifold; retaining said assembly substrate with a first frame portion; wherein said assembly substrate includes a plurality of openings; retaining a seed substrate adjacent to said assembly substrate such that said liquid phase material is introduced into a template within said assembly substrate and contacts a surface of said seed substrate through said plurality of openings; controlling melting and cooling of said liquid phase epitaxial material within said assembly substrate so as to form an epitaxial layer; controlling a temperature of said liquid phase epitaxial material at or below a re-melting temperature of the bulk of said epitaxial layer while or before moving said first frame portion and/or a second base portion so as to separate said epitaxial layer from said seed substrate; wherein said epitaxial layer can be transferred as a distinct layer from said seed substrate. ### Claim 20 (depends on 19) The method of claim 19 wherein a constant temperature lower than a melt temperature of said liquid phase epitaxial material is maintained at an interface to said seed substrate so that said liquid phase epitaxial material precipitates and grows epitaxially on a crystalline seed substrate. ### Claim 21 (depends on 19) The method of claim 19 wherein said assembly substrate, said seed substrate and a melt situate for the liquid phase epitaxial material are independently temperature controlled. ### Claim 22 (depends on 21) The method of claim 21 wherein said assembly substrate, said seed substrate and said melt situate are controlled to have a temperature at or slightly above a bulk melting temperature of said liquid phase epitaxial material during a first phase of said forming of said epitaxial layer. ### Claim 23 (depends on 22) The method of claim 22 wherein said assembly substrate, said seed substrate and said melt situate are slowly cooled to have a temperature at or slightly below a super-cooling point of said liquid phase epitaxial material during a second phase of said forming of said epitaxial layer. ### Claim 24 (depends on 23) The method of claim 23 wherein said assembly substrate and said seed substrate are further cooled to an ambient temperature after said separation during a third phase of said forming of said epitaxial layer.