Analysis of trimethylgallium decomposition by high-resolution mass spectrometry
Zheng Ye, Shugo Nitta, Yoshio Honda, Markus Pristovsek, Hiroshi Amano
Abstract
Abstract The decomposition of trimethylgallium (Ga(CH 3 ) 3 ) was examined under H 2 and N 2 atmospheres using a high-resolution (about 0.002 u) time-of-flight mass spectrometry system, which enabled the separation of N 2 and ethene (C 2 H 4 ) signals. Under H 2 atmosphere, the main decomposition product was methane (CH 4 ) formed by the hydrogenolysis of Ga(CH 3 ) 3 . However, under N 2 atmosphere, the main product is ethane (C 2 H 6 ) at temperature lower than 660 °C. Above 660 °C, the C 2 H 6 further decomposes into CH 4 , acetylene (C 2 H 2 ) and C 2 H 4 , and the main components in the gas phase are C 2 H 2 and C 2 H 4 above 1000 °C. Since these are effective carbon dopants, the molar ratio of H 2 to the Ga(CH 3 ) 3 raw material in the carrier gas should be maintained above 300 to inhibit the formation of hydrocarbons in N 2 .