Width Effect on Hot-Carrier-Induced Degradation for 90 nm Partially Depleted SOI CMOSFETs

Abstract

The hot-carrier-induced degradation of partially depleted silicon-on-insulator complementary metal-oxide-semiconductor field-effect transistors (CMOSFETs) at various applied voltages was investigated using 90 nm body-contact silicon-on-insulator (BC-SOI) devices with 1.6 nm gate oxides and various gate widths. In this work, a small gate-width device with a large drain current density was observed to suffer from serious hot-carrier-induced degradation. By inspecting the gate current (IG) degradation, the quality of gate oxide was observed to decay apparently after hot-carrier stressing. For a 90 nm BC-SOI nMOSFET of 1.2 µm narrow gate width, the tolerance of 1.6 nm ultra thin gate oxide layer was very low particularly around the channel edge region; thus, device reliability is very critical and easily degraded because of device gate oxide breakdown after hot-carrier stressing.