The plasma anodization to exhaustion of thin aluminium films on silicon substrates

Plasma anodization is a low temperature process that is of interest in the preparation of insulating films on semiconductors because of its effect in reducing the possibility of dissociation of the semiconductor.It has previously been applied to the formation of aluminum oxide layers on silicon and it is now demonstrated that the onset of substrate oxidation can be recognized electrically during the anodization. A model for the anodic process is presented in terms of electron and ion transport through the growing layer. Chemical information is presented and sources of contamination are identified. The films have high resistivities and breakdown strengths and MOS measurements are presented.It is expected that this monitoring technique could be applied to other material systems.