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Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire

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Show simple item record Song, T.L. Chua, Soo-Jin Fitzgerald, Eugene A. 2003-12-20T19:39:44Z 2003-12-20T19:39:44Z 2002-01
dc.description.abstract 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. en
dc.description.sponsorship Singapore-MIT Alliance (SMA) en
dc.format.extent 236285 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.relation.ispartofseries Advanced Materials for Micro- and Nano-Systems (AMMNS);
dc.subject graded InGaN buffers en
dc.subject strain relaxation en
dc.subject GaN/InGaN epliayers en
dc.subject sapphire en
dc.subject V-pits en
dc.title Graded InGaN Buffers for Strain Relaxation in GaN/InGaN Epliayers Grown on Sapphire en
dc.type Article en

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