Reaction chemistry of GaAs precursors
There has been recent interest in finding a less hazardous substitute for arsine in the MOCVD of GaAs and related compounds. These materials should exhibit lower vapor pressures and a higher LD[sub 50] threshold. However, what is the consequence, to film growth, of the change in arsenic sources from the hydride to the metalorganic is unknown. This had led to studies involving the fundamental chemistry of these reagents. Part of the investigation has involved the study of the chemistry of the decomposition reactions of these new sources with an without the presence of a metalorganic gallium sources (i.e. trimethyl and triethyl gallium). To that end researchers have used in-situ mass spectroscopy to follow these reactions. The result of these efforts suggests that in the presence of a gallium alkyl, and acid-base adduct is formed between Ga and As. Unfortunately, the data to support the non-volatile adduct formation is indirect by mass spectroscopy. This work utilized FTIR spectroscopy to monitor, in-situ, the reaction between triethyl or trimethyl gallium and t-butyl or arsine. It was felt that by following the relative change in specific IR spectra peak heights and position, that the extent of the gas phase reaction and possible adduct formation could be determined. The author fabricated a small reactor of FTIR in-situ monitoring. From the IR spectra obtained, the mixture of gallium and arsenic precursors, the author choose to concentrate the efforts on the As-H frequency due to the intensity and sharpness. An IR spectrum of the residual on the windows after evacuating the system may indicated the formation of a non-volatile adduct. The author has found direct evidence for the formation of an adduct between GaAs precursors. Additionally, it shows that FTIR spectroscopy is a well technique for in-situ monitoring those precursors at room temperature.
- Research Organization:
- Polytechnic Univ., Brooklyn, NY (United States)
- OSTI ID:
- 6988151
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360601* -- Other Materials-- Preparation & Manufacture
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ADDUCTS
ARSENIC COMPOUNDS
ARSENIDES
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMICAL VAPOR DEPOSITION
DEPOSITION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INFRARED SPECTRA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PNICTIDES
PRECURSOR
SPECTRA
SURFACE COATING