The ultraviolet absorption spectra of selected organometallic compounds used in the chemical vapor deposition of gallium arsenide.

Ultraviolet absorption spectra and absolute absorption cross sections of trimethylgallium (Ch sub 3) sub 3 Ga, triethylgallium (C sub 2 H sub 5) sub 3 Ga, trimethylarsine (CH sub 3) sub 3 As, and triethylarsine (C sub 2 H sub 5) sub 3 As have been recorded as a function of temperature. Room temperature peak absorption cross sections of 2.62 x 10 sup (-17), 1.0 x 10 sup (-19), 5.6 x 10 sup (-17), and 3.1 x 10 sup (-17) cm sup 2 respectively were obtained for the above compounds at ~ 195. 0, 195.0, 201.0, and 208,5 nm. (CH sub 3) sub 3 As and (C sub 2 H sub 5) sub 3 As were found to be thermally stable up to 350C, whereas (CH sub 3) sub 3 Ga and (C sub 2 H sub 5) sub 3 Ga began to show decomposition at approximately 350C. This resolves previous discrepancies in the absorption cross section for (CH sub 3) sub 3 Ga, and provides data for photo- enhanced deposition studies and optical diagnostic measurements in conventional chemical vapor deposition.