Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Spectroscopic ellipsometry studies of GaN films deposited by reactive rf sputtering of GaAs target
|
|
Creator |
BISWAS, A
BHATTACHARYYA, D SAHOO, NK YADAV, BS MAJOR, SS SRINIVASA, RS |
|
Subject |
light-emitting-diodes
optical-properties polycrystalline gan thin-films hexagonal gan amorphous-semiconductors si substrate in-situ growth ultraviolet |
|
Description |
GaN films have been deposited by reactive rf sputtering of GaAs target in 100% nitrogen ambient on quartz substrates at different substrate temperatures ranging from room temperature to 700 degrees C. A series of films, from arsenic-rich amorphous to nearly arsenic-free polycrystalline hexagonal GaN, has been obtained. The films have been characterized by phase modulated spectroscopic ellipsometry to obtain the optical parameters, viz., fundamental band gap, refractive index, and extinction coefficient, and to understand their dependence on composition and microstructure. A generalized optical dispersion model has been used to carry out the ellipsometric analysis for amorphous and polycrystalline GaN films and the variation of the optical parameters of the films has been studied as a function of substrate temperature. The refractive index values of polycrystalline films with preferred orientation of crystallites are slightly higher (2.2) compared to those for amorphous and randomly oriented films. The dominantly amorphous GaN film shows a band gap of 3.47 eV, which decreases to 3.37 eV for the strongly c-axis oriented polycrystalline film due to the reduction in amorphous phase content with increase in substrate temperature. (c) 2008
|
|
Publisher |
AMER INST PHYSICS
|
|
Date |
2011-07-16T15:09:46Z
2011-12-26T12:49:50Z 2011-12-27T05:35:34Z 2011-07-16T15:09:46Z 2011-12-26T12:49:50Z 2011-12-27T05:35:34Z 2008 |
|
Type |
Article
|
|
Identifier |
JOURNAL OF APPLIED PHYSICS, 103(8), -
0021-8979 http://dx.doi.org/10.1063/1.2903443 http://dspace.library.iitb.ac.in/xmlui/handle/10054/4459 http://hdl.handle.net/10054/4459 |
|
Language |
en
|
|