Enhanced reliability and uniformity for Ge pMOSFET with low temperature supercritical fluid treatment

Abstract

Significant improvement on uniformity and reliability characteristics in Ge pMOSFET are achieved with a novel low temperature supercritical phase CO 2 fluid treatment with H 2 O cosolvent. Devices with the proposed treatment also exhibit a lower subthreshold swing, a higher on/off current ratio, and a lower interface trap density. The improvement can be attributed to the reduction of oxygen vacancy and low oxidation states in the interfacial layer (IL), and the quality enhancement on both IL and high-k gate stack. • A low temperature supercritical phase CO 2 fluid with H 2 O cosolvent treatment was proposed. • The uniformity and reliability characteristics of p-channel Ge transistor can be improved. • Improvement can be attributed to reduction of oxygen vacancy and low oxidation states. • The process is promising for the mass production of chip on large-size wafers.