Investigation of Temperature Dependence of mmWave Power Amplifier Large-Signal Reliability Performance

Abstract

This work aims to study the temperature dependence on the long-term reliability of a power amplifier (PA) cell fabricated using 40-nm partially depleted-silicon on insulator (PD-SOI) nFET under dc and large-signal RF stress. Voltage swing caused by large RF signals complicates the stress mechanism due to frequent switching of stress from conducting to nonconducting. The impact of temperature on the time slope exponent ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> ) is also analyzed to understand the degradation mechanism at different temperatures. The values of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> are found to increase with the temperature pointing to the generation of new defects at the interface. A comparative reliability analysis is presented for dc, small-, and large-signal performance under varied accelerated dc and large-signal stress at drain and gate for different temperatures. Unity gain frequencies are also temperature sensitive and show high degradation at elevated temperatures. In our study, we have investigated the lifetime as a function of temperature of the PA operating in compression. It is observed that the lifetime is more than ten years when the PA operates at room temperature, which deteriorates as the measurement chuck temperature rises.