# US 11,078,597 B2 · Method for making epitaxial structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,597 B2 - Document ID: US11078597B2 - Status: Granted - Kind: B2 - Application number: 15/434,034 - Filed: 2017-02-15 - Published: 2017-06-15 - Granted: 2021-08-03 - Earliest claimed: 2012-03-28 - Assignees: Tsinghua University; Hon Hai Precision Industry Co., Ltd. - Applicants: Tsinghua University; Hon Hai Precision Industry Co., Ltd. - Inventors: Yang Wei; Shou-Shan Fan - Web page: https://patentgrep.com/patent/US11078597B2 ## CPC - C30B 25/183: {being provided with a buffer layer, e.g. a lattice matching layer} - C30B 25/186: {being specially pre-treated by, e.g. chemical or physical means} - C30B 29/406: {Gallium nitride} - H10K 85/221: {Carbon nanotubes} - H10P 14/272: {using mask materials other than SiO2 or SiN} - H10P 14/2901: {Materials} - H10P 14/3202: {Materials thereof} - H10P 14/3216: {Nitrides} - H10P 14/3402: {characterised by the chemical composition} - H10P 14/3416: {Nitrides} - H10P 14/38: {characterised by treatments done after the formation of the materials} - C30B 19/00: Liquid-phase epitaxial-layer growth - C30B 25/00: Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth - C30B 25/02: Epitaxial-layer growth - C30B 25/04: Pattern deposit, e.g. by using masks - C30B 25/10: Heating of the reaction chamber or the substrate - C30B 29/38: Nitrides - 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 - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A method for making an epitaxial structure includes the following steps. A substrate having an epitaxial growth surface is provided. A carbon nanotube layer is placed on the epitaxial growth surface. A buffer layer is formed on the epitaxial growth surface. A first epitaxial layer is epitaxially grown on the buffer layer. The substrate and the buffer layer are separated to form a second epitaxial growth surface. A second epitaxial layer is epitaxially grown on the second epitaxial growth surface. ## Claims ### Claim 1 A method for making epitaxial structure, the method comprising: placing a carbon nanotube layer on a first epitaxial growth surface of a substrate, wherein the carbon nanotube layer comprises a plurality of carbon nanotubes, the carbon nanotube layer defines a plurality of apertures, a portion of the first epitaxial growth surface is exposed from the plurality of apertures; epitaxially growing a buffer layer on the portion of the first epitaxial growth surface exposed from the plurality of apertures, wherein the buffer layer comprises a first surface in contact with the first epitaxial growth surface and a second surface opposite to the first surface; growing a first epitaxial layer on the second surface of the buffer layer, wherein a plurality of first grooves is formed in the first epitaxial layer, and the plurality of carbon nanotubes is embedded in the plurality of first grooves; exposing the first surface of the buffer layer by removing the substrate, wherein the buffer layer is kept on the first epitaxial layer after removing the substrate; and growing a second epitaxial layer on the first surface of the buffer layer, wherein the second epitaxial layer is grown from the first surface of the buffer layer, and the buffer layer is sandwiched between the second epitaxial layer and the first epitaxial layer after growing the second epitaxial layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the growing the buffer layer comprises forming a plurality of second grooves on the buffer layer. ### Claim 3 (depends on 2) The method of claim 2, wherein the growing the buffer layer further comprises embedding the carbon nanotube layer in the plurality of second grooves and exposing the carbon nanotube layer out of the buffer layer from the plurality of second grooves. ### Claim 4 (depends on 1) The method of claim 1, wherein the first epitaxial growth surface comprises an exposed part, the exposed part is exposed from the plurality of apertures, and the buffer layer is grown on the exposed part and through the plurality of apertures. ### Claim 5 (depends on 4) The method of claim 4, wherein sizes of the plurality of apertures are in a range from about 10 nanometers to about 500 micrometers. ### Claim 6 (depends on 4) The method of claim 4, wherein a duty factor of the carbon nanotube layer is in a range from about 1:4 to about 4:1. ### Claim 7 (depends on 1) The method of claim 1, wherein the plurality of carbon nanotubes extends along a direction substantially parallel to the first epitaxial growth surface. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of carbon nanotubes extends along a crystallographic orientation of the substrate. ### Claim 9 (depends on 1) The method of claim 1, wherein the substrate and the buffer layer are separated by laser irradiation, corrosion, or thermal expansion and contraction. ### Claim 10 (depends on 1) The method of claim 1, wherein the carbon nanotube layer is free-standing and placed on the first epitaxial growth surface directly. ### Claim 11 (depends on 1) The method of claim 1, wherein the carbon nanotube layer is kept on the first epitaxial layer after removing the substrate and sandwiched between the second epitaxial layer and the first epitaxial layer after growing the second epitaxial layer. ### Claim 12 (depends on 1) The method of claim 1, wherein the carbon nanotube layer is treated with an organic solvent after being placed on the first epitaxial growth surface so that the carbon nanotube layer is attached on the first epitaxial growth surface. ### Claim 13 (depends on 12) The method of claim 12, wherein the organic solvent is applied to an entire surface of the carbon nanotube layer. ### Claim 14 (depends on 12) The method of claim 12, wherein entirety of the carbon nanotube layer is immersed in the organic solvent. ### Claim 15 (depends on 12) The method of claim 12, wherein the organic solvent is selected from the group consisting of ethanol, methanol, acetone, dichloroethane, chloroform, and mixtures thereof. ### Claim 16 (depends on 1) The method of claim 1, wherein the plurality of carbon nanotubes are embedded in the first epitaxial layer when growing the first epitaxial layer on the second surface of the buffer layer. ### Claim 17 (depends on 1) The method of claim 1, wherein the plurality of carbon nanotubes are embedded in the first epitaxial layer when growing the first epitaxial layer on the second surface of the buffer layer. ### Claim 18 A method for making epitaxial structure, the method comprising: placing a carbon nanotube layer on a first epitaxial growth surface of a substrate, wherein the carbon nanotube layer comprises a plurality of carbon nanotubes, the carbon nanotube layer defines a plurality of apertures, a portion of the first epitaxial growth surface is exposed from the plurality of apertures; epitaxially growing a buffer layer on the portion of the first epitaxial growth surface exposed from the plurality of apertures, wherein the buffer layer comprises a first surface in contact with the first epitaxial growth surface and a second surface opposite to the first surface; growing a first epitaxial layer on the second surface of the buffer layer, wherein a plurality of first grooves is formed in the first epitaxial layer, and the plurality of carbon nanotubes is embedded in the plurality of first grooves; exposing the first surface of the buffer layer by removing the substrate, wherein the buffer layer is kept on the first epitaxial layer after removing the substrate; and growing a second epitaxial layer on the first surface of the buffer layer, wherein the second epitaxial layer is grown from the first surface of the buffer layer, so that the carbon nanotube layer is sandwiched between the first epitaxial layer and the second epitaxial layer, and the buffer layer is sandwiched between the second epitaxial layer and the first epitaxial layer after growing the second epitaxial layer. ### Claim 19 A method for making epitaxial structure, the method comprising: placing a carbon nanotube layer on a first epitaxial growth surface of a substrate, wherein the carbon nanotube layer defines a plurality of apertures, a portion of the first epitaxial growth surface is exposed from the plurality of apertures; growing a buffer layer on the first epitaxial growth surface exposed from the plurality of apertures; growing a first epitaxial layer on the buffer layer, so that the carbon nanotube layer is between the substrate and the first epitaxial layer; removing the substrate to expose the buffer layer; and growing a second epitaxial layer on the exposed buffer layer, so that the buffer layer is sandwiched between the second epitaxial layer and the first epitaxial layer after growing the second epitaxial layer.