Effects of Wet Chemical and Trimethyl Aluminum Treatments on the Interface Properties in Atomic Layer Deposition of Al₂O₃ on InAs

Abstract

The reduction of native oxides on an InAs surface using various wet and dry chemical treatments, including hydrochloric acid (HCl) treatment, sulfide treatment, and in situ trimethyl aluminum (TMA) treatment before the atomic layer deposition (ALD) of Al 2 O 3 on InAs is studied. X-ray photoelectron spectrum (XPS) results show that the effect of surface cleaning by TMA was apparent almost after the first pulse but that TMA cleaning is not as effective as wet chemical surface cleaning. The combination of wet chemical treatment and TMA pretreatment is the most effective method for InAs surface cleaning, as indicated by the XPS analysis. Capacitance–voltage ( C – V ) and current density–voltage ( J – V ) characteristics on metal–oxide–semiconductor capacitance (MOSCAP) structures were also investigated to evaluate the Al 2 O 3 /n-InAs interface quality after different surface treatments, and the results are consistent with the XPS analysis.