A method of forming a transistor is disclosed, in which gate-to-substrate leakage is addressed by forming and maintaining a conformal oxide layer overlying the transistor gate. Using the method disclosed for an n-type device, the conformal oxide layer can be formed as part of the source-drain doping process. Subsequent removal of residual phosphorous dopants from the surface of the oxide layer is accomplished without significant erosion of the oxide layer. The removal step uses a selective deglazing process that employs a hydrolytic reaction, and an acid-base neutralization reaction that includes an ammonium hydroxide component.