COMPARATIVE-STUDY ON CARBON INCORPORATION IN MOCVD ALGAAS LAYERS BETWEEN ARSINE AND TERTIARYBUTYLARSINE

We have studied the carbon incorporation properties in MOCVD Al0.7Ga0. 3As epilayers on differently oriented surfaces by using either arsine or tertiarybutylarsine (TBAs). The present study has shown that the ca rbon incorporation in the layers using TBAs is significantly lower tha n that using AsH3 under higher V/III ratio and/or lower temperature co nditions. The results also indicate that the carbon does not originate in TBAs but in TMG and TMA. According to these results, the carbon in corporation mechanism is discussed through analysis of reaction produc ts by growth. A growth model in which As molecules rather than H atoms act on the carbon elimination from the growth surface is presented.