A ballistic electron emission microscopy (BEEM)-investigation of the effects of reactive ion etching (RIE) and of chemical pretreatment on III-V semiconductors

摘要

Ballistic electron emission microscopy (BEEM) has been applied to determine the Schottky barrier height change of contacts on III-V substrates due to classical processing treatments. In the case of GaAs a dry etch using SiCl_4 was studied. The distribution of barrier heights over the contact area could be measured. Dry etching was found to introduce a second Gaussian distribution, with lower mean barrier height, next to the Gaussian distribution already found for wet etched reference samples. For InP, a HF-treatment was found to affect the barrier height distribution. Models are proposed to account for these findings.