Phosphoric acid-peroxide mixture surface preparation for the improvement of InGaAs channel characteristics

Abstract

InGaAs is a potential candidate for a next-generation channel material of complementary metal-oxide-semiconductor devices based on its excellent electron mobility. In this study, the surface behaviors of the InGaAs after treatments in H3PO4/H2O2/H2O and HNO3/H2O2/H2O mixtures were investigated and compared with that after treatment in a HCl/H2O2/H2O mixture. Although the presence of Cl− in an acidic solution suppressed the overall etching reaction and material loss of the InGaAs surface, Cl− induced the roughening of the InGaAs surface. The smallest InGaAs/Al2O3 interface charge trap density was observed when the InGaAs surface was prepared in the H3PO4/H2O2/H2O solution. It was also confirmed that the H3PO4/H2O2/H2O-treated InGaAs surface had the highest electron mobility among the samples and the lowest interfacial defect density, such as arsenic vacancies and antisites. Finally, it was concluded that surface preparation of InGaAs with H3PO4/H2O2/H2O effectively improved the interfacial electrical properties at the metal-oxide-InGaAs semiconductor by successfully minimizing surface roughening and the interfacial defect density compared to a well-known HCl/H2O2/H2O solution process.