Salicide process for submicron bicmos technology

Abstract EN

Simultaneous titanium salicide formation on doped/undoped Si and Polysilicon (poly-Si) can be accompanied by undesirable materials effects such as: salicide lateral growth over the sidewall spacer oxide and hence bridging of the gate to source/drain (S/D), Ti reaction with the field oxide, resulting in global shorting of devices and circuits, and variations in salicide properties depending on dopant concentration/type in the Si.

To understand the interaction mechanisms, experiments were carried out to study the salicide growth rates, dopant/salicide reactions, rapid thermal processing (RTP) of poly-Si salicidation, Ti/oxide interactions, and salicide lateral growth as a function of temperature and process window.

Salicided BiCMOS devices were characterized by SEM, contact resistance, sheet resistance, and unction leakage current measurements.

The optimized salicide process exhibited characteristics suitable for submicron devices.