dc.contributor.author | Song, T.L. | |
dc.contributor.author | Chua, Soo-Jin | |
dc.contributor.author | Fitzgerald, Eugene A. | |
dc.date.accessioned | 2003-12-20T19:39:44Z | |
dc.date.available | 2003-12-20T19:39:44Z | |
dc.date.issued | 2002-01 | |
dc.identifier.uri | http://hdl.handle.net/1721.1/3975 | |
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 |