Methods of forming field effect transistors using disposable aluminum oxide spacers

Abstract

Methods of forming a field effect transistor by forming a gate electrode on a semiconductor substrate and forming aluminum oxide spacers on sidewalls of the gate electrode. Source and drain region dopants of first conductivity type are implanted into the semiconductor substrate using the aluminum oxide spacers as an implant mask. Thereafter, the aluminum oxide spacers are selectively removed by exposing them to tetramethyl ammonium hydroxide (TMAH). The step of selectively removing the aluminum oxide spacers may include exposing the aluminum oxide spacers to tetramethyl ammonium hydroxide having a temperature of about 80° C.