학술논문
Advances in selective wet oxidation of AlGaAs alloys
Document Type
Periodical
Author
Source
IEEE Journal of Selected Topics in Quantum Electronics IEEE J. Select. Topics Quantum Electron. Selected Topics in Quantum Electronics, IEEE Journal of. 3(3):916-926 Jun, 1997
Subject
Language
ISSN
1077-260X
1558-4542
1558-4542
Abstract
We review the chemistry, microstructure, and processing of buried oxides converted from AlGaAs layers using wet oxidation. Hydrogen is shown to have a central role in the oxidation reaction as the oxidizing agent and to reduce the intermediate predict As/sub 2/O/sub 3/ to As. The stable oxide is amorphous (Al/sub x/Ga/sub 1-x/)/sub 2/O/sub 3/ which has no defects along the oxide/semiconductor interfaces but can exhibit strain at the oxide terminus due to volume shrinkage. The influence of gas flow, gas composition, temperature, Al-content, and layer thickness on the oxidation rate are characterized to establish a reproducible process. Linear oxidation rates with Arrhenius activation energies which strongly depend upon AlAs mole fraction are found. The latter produces strong oxidation selectivity between AlGaAs layers with slightly differing Al-content. Oxidation selectivity to thickness is also shown for layer thickness