Open AccessIn-situ optical photoreflectance during MOCVD
Author(s) -
William G. Breiland,
B. E. Hammons,
Hongwei Hou,
Xu Mei
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/564267
Subject(s) - metalorganic vapour phase epitaxy , doping , chemical vapor deposition , in situ , impurity , materials science , semiconductor , optoelectronics , thin film , calibration , characterization (materials science) , compound semiconductor , phase (matter) , deposition (geology) , analytical chemistry (journal) , nanotechnology , chemistry , epitaxy , physics , organic chemistry , paleontology , quantum mechanics , sediment , biology , layer (electronics)
This report summarizes the development of in situ optical photoreflectance as a tool for measuring impurity concentrations in compound semiconductors. The authors have successfully explored the use of photoreflectance as an in situ tool for measuring n-type doping levels in metal-organic chemical vapor deposition (MOCVD) grown GaAs materials. The technique measures phase and frequency shifts in Franz-Keldysh oscillations measured on uniformly doped thin films. Doping concentrations from 5 {times} 10{sup 16} to 1 {times} 10{sup 18} can be measured at temperatures below 130 C. A method has been developed to include photoreflectance as the last step in the pre-growth in situ calibration procedure for MOCVD thin film structures. This combined capability now enables one to rapidly and accurately determine growth rates, chemical composition, and doping levels necessary to generate a recipe to fabricate complex optoelectronic compound semiconductor devices