Application of Cl2/BCl3/Ar plasma treatment in the improvement of Ti/Al/Mo/Au ohmic contacts

Abstract

Significant improvement of Ti/Al/Mo/Au ohmic contacts deposited on previously Cl2/BCl3/Ar plasma treated surface was observed. The standard deviation of contact resistance was crucially reduced due to the incorporation of Cl2/BCl3/Ar plasma treatment. The Cl2:BCl3:Ar gas mixture was used in order to thin the top of AlGaN layer prior to deposition of Ti/Al/Mo/Au ohmic contacts. The surface morphology of AlGaN was investigated using scanning electron microscopy and atomic force microscopy. TLM measurements revealed a consequential decrease of contact resistivity.