The Effect of Interfacial Contamination on Antiphase Domain Boundary Formation in GaAs on Si(100)

Abstract

The suppression of defects such as antiphase domain boundaries (APBs) is a key challenge in the effort to integrate III-V compound semiconductor devices on Si. The formation of APBs naturally arises from growing a polar material on a nonpolar substrate. Surface contamination present on the substrate prior to growth can also disrupt the ordering of atoms in an epitaxial layer and lead to extended defects. In this study, the amount of contamination on Si(100) wafers was varied by approximately an order of magnitude to investigate the effect on formation of APBs in an epitaxial GaAs film grown by MOCVD. The results indicate a direct correlation between the interfacial oxygen and carbon impurity dose and the APB density.

Determination of Antiphase Domain Boundary Annihilation Rate in GaAs on Si(001) and the Influence of MOCVD Growth Temperature

“…Samples were then dipped in a HF(49%):HNO3(69%):H2O (10:1:3) solution for a short time (<10s) to selectively etch down APBs. This HF/HNO3 etchant has been shown to be selective for APBs (18) and thus can improve the contrast of APB features under a scanning electron microscope (SEM). Images of the sample surfaces were taken with a FEI Nova NanoSEM 430 SEM.…”

Application of Cl2 for low temperature etch and epitaxy

“…For rather long time SiO 2 removal, which typically consisted of so-called HF-dip and a hydrogen bake, presented a challenge since it was difficult to reduce the bake temperature below 800 °C. The adoption of integrated low temperature pre-epi clean chambers (Siconi TM (AMAT) or Previum TM (ASM)) which can effectively remove native SiO 2 at temperatures below 200 °C changed this situation dramatically [3,4]. In terms of thermal budget, the focus now shifts from the pre-epi clean to epitaxy itself, which defines the highest process temperature.…”