Characterization and Analysis of Hot Carrier Degradation Under DC and Large-Signal RF Stress in a PDSOI Floating-Body NFET-Based Power Amplifier Cell Under WiFi Operating Conditions

Abstract

This paper presents an extensive experimental analysis of hot carrier degradation (HCD) due to DC and large-signal RF stress on a power amplifier (PA) cell in the sub-7GHz frequency band. The reported PA cell is fabricated in a 45-nm RFSOI technology and consists of a single n-channel floating body partially depleted SOI FET. The impact of HCD on the class, conduction angle ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta $ </tex-math></inline-formula> ), and performance of the PA cell is analyzed under DC and large-signal RF stress conditions. Generation of defects and their types, i.e., whether oxide or interface traps, are understood using a combination of RF and DC stress conditions. Our detailed analysis distinguishes HCD mechanisms dominated by oxide and interface traps by studying time slope exponents, changes in the subthreshold swing, threshold voltage, and peak transconductance. The impact of RF stress on the PA cell lifetime is also extracted using a semiempirical model.