Optimization and Characterization of Phosphorus Diffused LPCVD Polysilicon Passivated Contacts with Low Pressure Tunnel Oxide

Abstract

This work presents the investigation of low pressure in-situ thermal oxidation as the interfacial oxide for n+ polysilicon-oxide passivated contact structure, achieving excellent surface passivation below 1 fA·cm-2 and contact resistivity below 1 mΩ·cm2. The results from the process optimisation are presented in detail, showing the importance of accurate control of oxidation conditions, and presenting the correlation to the electrical properties. Additionally, a method of fabricating contact resistivity structures from symmetrical photoconductance decay lifetime samples, and the extraction of the specific contact resistivity using 3D numerical simulation is presented.