Application of the Taguchi method for assessment of surface treatment procedures for Ti/n-type GaN contacts

Abstract

A Taguchi approach was used to appraise the relative importance of gallium nitride surface preparation on the processing of Ti/n-type GaN contacts. It is shown that a potassium hydroxide etch, silicon tetrachloride etch or hydrochloric acid clean prior to metal deposition can significantly improve the performance of the contact for the criteria of metal adhesion, contact resistance, electrical behaviour and across wafer uniformity.