Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire
Graded InGaN buffers are employed to relax the strain arising from the lattice and thermal mismatches between GaN/InGaN epilayers grown on sapphire. The formation of V-pits in linearly graded InGaN/GaN bulk epilayers is illustrated. The V-pits were sampled using Atomic Force Microscopy and Scanning...
| Main Authors: | , , |
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| Format: | Article |
| Language: | en_US |
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2003
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| Online Access: | http://hdl.handle.net/1721.1/3975 |
| _version_ | 1826203662629732352 |
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| author | Song, T.L. Chua, Soo-Jin Fitzgerald, Eugene A. |
| author_facet | Song, T.L. Chua, Soo-Jin Fitzgerald, Eugene A. |
| author_sort | Song, T.L. |
| collection | MIT |
| description | Graded InGaN buffers are employed to relax the strain arising from the lattice and thermal mismatches between GaN/InGaN epilayers grown on sapphire. The formation of V-pits in linearly graded InGaN/GaN bulk epilayers is illustrated. The V-pits were sampled using Atomic Force Microscopy and Scanning Electron Microscopy to examine their variation from the theoretical geometry shape. We discovered that the size of the V-pit opening in linearly graded InGaN, with and without GaN cap layer, has a Gaussian distribution. As such, we deduce that the V-pits are produced at different rates, as the growth of the InGaN layer progresses. In Stage I, the V-pits form at a slow rate at the beginning and then accelerate in Stage II when a critical thickness is reached before decelerating in Stage III after arriving at a mean size. It is possible to fill the V-pits by growing a GaN cap layer. It turns out that the filling of the V-pits is more effective at lower growth temperature of the GaN cap layer and the size of the V-pits opening, which is continued in to GaN cap layer, is not dependent on the GaN cap layer thickness. Furthermore, graded InGaN/GaN layers display better strain relaxation as compared to conventionally grown bulk GaN. By employing a specially design configuration, the V-pits can be eliminated from the InGaN epilayer. |
| first_indexed | 2024-09-23T12:41:06Z |
| format | Article |
| id | mit-1721.1/3975 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:41:06Z |
| publishDate | 2003 |
| record_format | dspace |
| spelling | mit-1721.1/39752019-04-10T08:59:40Z Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire Song, T.L. Chua, Soo-Jin Fitzgerald, Eugene A. graded InGaN buffers strain relaxation GaN/InGaN epliayers sapphire V-pits Graded InGaN buffers are employed to relax the strain arising from the lattice and thermal mismatches between GaN/InGaN epilayers grown on sapphire. The formation of V-pits in linearly graded InGaN/GaN bulk epilayers is illustrated. The V-pits were sampled using Atomic Force Microscopy and Scanning Electron Microscopy to examine their variation from the theoretical geometry shape. We discovered that the size of the V-pit opening in linearly graded InGaN, with and without GaN cap layer, has a Gaussian distribution. As such, we deduce that the V-pits are produced at different rates, as the growth of the InGaN layer progresses. In Stage I, the V-pits form at a slow rate at the beginning and then accelerate in Stage II when a critical thickness is reached before decelerating in Stage III after arriving at a mean size. It is possible to fill the V-pits by growing a GaN cap layer. It turns out that the filling of the V-pits is more effective at lower growth temperature of the GaN cap layer and the size of the V-pits opening, which is continued in to GaN cap layer, is not dependent on the GaN cap layer thickness. Furthermore, graded InGaN/GaN layers display better strain relaxation as compared to conventionally grown bulk GaN. By employing a specially design configuration, the V-pits can be eliminated from the InGaN epilayer. Singapore-MIT Alliance (SMA) 2003-12-20T19:39:44Z 2003-12-20T19:39:44Z 2002-01 Article http://hdl.handle.net/1721.1/3975 en_US Advanced Materials for Micro- and Nano-Systems (AMMNS); 236285 bytes application/pdf application/pdf |
| spellingShingle | graded InGaN buffers strain relaxation GaN/InGaN epliayers sapphire V-pits Song, T.L. Chua, Soo-Jin Fitzgerald, Eugene A. Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title | Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title_full | Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title_fullStr | Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title_full_unstemmed | Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title_short | Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire |
| title_sort | graded ingan buffers for strain relaxation in gan ingan epliayers grown on sapphire |
| topic | graded InGaN buffers strain relaxation GaN/InGaN epliayers sapphire V-pits |
| url | http://hdl.handle.net/1721.1/3975 |
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