# US 8,541,772 B2 · Nitride semiconductor stacked structure and method for manufacturing same and nitride semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,772 B2 - Document ID: US8541772B2 - Status: Granted - Kind: B2 - Application number: 13/223,853 - Filed: 2011-09-01 - Published: 2012-08-23 - Granted: 2013-09-24 - Earliest claimed: 2011-02-18 - Assignees: Kabushiki Kaisha Toshiba - Applicants: Hideto Sugawara - Inventors: Hideto Sugawara - Web page: https://patentgrep.com/patent/US8541772B2 ## CPC - H10H 20/819: characterised by their shape, e.g. curved or truncated substrates - H10H 20/01335: {the light-emitting regions comprising nitride materials} - H10P 14/24: using chemical vapour deposition [CVD] - H10P 14/271: {characterised by the preparation of substrate for selective deposition} - H10P 14/2901: {Materials} - H10P 14/3216: {Nitrides} - H10P 14/3251: {consisting of three or more layers} - H10P 14/3416: {Nitrides} - H10P 14/3444: {P-type} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract According to one embodiment, a nitride semiconductor stacked structure having a first surface includes a substrate, a first buffer layer, a first crystal layer, a second buffer layer and a second crystal layer. A step portion is provided in the substrate and includes an upper surface, a lower surface, and a side surface between the upper surface and the lower surface. The first buffer layer includes InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and covers the lower surface and the side surface. The first crystal layer is provided on the first buffer layer, includes InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and has an upper surface provided above the upper surface of the substrate. The second buffer layer includes InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and continuously covers the upper surface of the first crystal layer and the upper surface of the substrate. The second crystal layer covers the second buffer layer, includes InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and has the first surface. ## Claims ### Claim 1 A nitride semiconductor stacked structure having a first surface on which a semiconductor including InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, x+y≦1) can be stacked, the structure comprising: a substrate having a step portion, the step portion including an upper surface, a lower surface, and a side surface between the upper surface and the lower surface; a first buffer layer including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and covering the lower surface and the side surface; a first crystal layer provided on the first buffer layer, including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and having an upper surface provided above the upper surface of the substrate; a second buffer layer including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and continuously covering the upper surface of the first crystal layer and the upper surface of the substrate; and a second crystal layer covering the second buffer layer, including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and having the first surface. ### Claim 2 (depends on 1) The structure according to claim 1, wherein a height of the step portion of the substrate is smaller than sum of a thickness of the first buffer layer and a thickness of the first crystal layer, and larger than a height difference between the upper surface of the first crystal layer and the upper surface of the substrate. ### Claim 3 (depends on 1) The structure according to claim 1, wherein the substrate is made of a hexagonal material, and the upper surface and the lower surface of the substrate are c-planes. ### Claim 4 (depends on 1) The structure according to claim 1, wherein the upper surface of the substrate is an upper surface of protrusions provided periodically in a direction parallel to the first surface, and the side surface of the step portion is a side surface of the protrusions. ### Claim 5 (depends on 4) The structure according to claim 4, wherein the protrusions are shaped like islands or stripes. ### Claim 6 A nitride semiconductor stacked structure having a first surface on which a semiconductor including InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, x+y≦1) can be stacked, the structure comprising: a substrate having a step portion, the step portion including an upper surface, a lower surface, and a side surface between the upper surface and the lower surface; a first buffer layer including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and covering the lower surface and the side surface; a first crystal layer provided on the first buffer layer, including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and having an upper surface provided above the upper surface of the substrate; a selective growth mask layer provided on the upper surface of the substrate; a second buffer layer including AlwGa1-wN (0.6≦w≦1) and continuously covering the upper surface of the first crystal layer and an upper surface of the selective growth mask layer; and a second crystal layer covering the second buffer layer, including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05), and having the first surface. ### Claim 7 (depends on 6) The structure according to claim 6, wherein a height of the step portion of the substrate is smaller than sum of a thickness of the first buffer layer and a thickness of the first crystal layer, and larger than a height difference between the upper surface of the first crystal layer and the upper surface of the substrate. ### Claim 8 (depends on 6) The structure according to claim 6, wherein the substrate is made of a hexagonal material, and the upper surface and the lower surface of the substrate are c-planes. ### Claim 9 (depends on 6) The structure according to claim 6, wherein the upper surface of the substrate is an upper surface of protrusions provided periodically in a direction parallel to the first surface, and the side surface of the step portion is a side surface of the protrusions. ### Claim 10 (depends on 9) The structure according to claim 9, wherein the protrusions are shaped like islands or stripes. ### Claim 11 (depends on 6) The structure according to claim 6, wherein the selective growth mask layer includes an insulating film or a metal film. ### Claim 12 A nitride semiconductor device comprising: a nitride semiconductor stacked structure including: a substrate having a step portion, the step portion including an upper surface, a lower surface, and a side surface between the upper surface and the lower surface; a first buffer layer including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and covering the lower surface and the side surface; a first crystal layer provided on the first buffer layer, including InsAltGa1-s-tN (0≦s≦0.05, 1≦t≦0.05), and having an upper surface provided above the upper surface of the substrate; a second buffer layer including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦1) and continuously covering the upper surface of the first crystal layer and the upper surface of the substrate; and a second crystal layer covering the second buffer layer and including InsAltGa1-s-tN (0≦s≦0.05, 0≦t≦0.05); and a semiconductor stacked on the second crystal layer and including InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, x+y≦1). ### Claim 13 (depends on 12) The device according to claim 12, wherein the upper surface of the substrate is an upper surface of protrusions provided periodically in a direction parallel to the first surface and shaped like islands or stripes, and the side surface of the step portion is a side surface of the protrusions. ### Claim 14 (depends on 13) The device according to claim 13, wherein the semiconductor includes an active layer which can emit light. ### Claim 15 (depends on 13) The device according to claim 13, wherein the substrate is made of a hexagonal material, and the upper surface and the lower surface of the substrate are c-planes. ### Claim 16 (depends on 15) The device according to claim 15, wherein the upper surface of the substrate is an upper surface of protrusions provided periodically in a direction parallel to the first surface and shaped like islands or stripes, and the side surface of the step portion is a side surface of the protrusions. ### Claim 17 (depends on 16) The device according to claim 16, wherein the semiconductor includes an active layer which can emit light.