The influence of hydrocarbons in MOVPE GaAs growth: Improved detection of carbon by secondary ion mass spectroscopy

Abstract

The quantitative measurement of carbon concentration in films grown by MOVPE is required to elucidate both the growth reactions and the influence of reaction-by-products. Secondary ion mass spectroscopy (SIMS) can determine the total carbon content in a layer and complement measurements of the electrically active carbon. The presence of carbon compounds in the residual gas background of SIMS instrument has typically limited the carbon detection limits to ∼1017 cm-3. We have developed alternative SIMS techniques for the detection of carbon by utilizing the analyte ion, As13C-, yielding detection limits down to 1014-1015 cm-3 for 13C in GaAs. We have applied this technique to the study of the incorporation of carbon from CH4 and isotropically enriched C2H2, C2H4, and C3H6 during the MOVPE growth of GaAs. © 1988.