Robustness Assessment Through 77GHz Operating Life Test of Power Amplifier for Radar Applications in 28nm FD-SOI CMOS

• Main Authors: Cacho, F., Cathelin, P., Hai, J., Bouvot, S., Nowakowski, J., Martinez, M., Debroucke, R., Jean, S., Paulin, R., Antonijevic, J., Federspiel, X., Planes, N., Papotto, G., Parisi, A., Finocchiaro, A., Cavarra, A., Castorina, A., Nocera, C., Palmisano, G.
• Format: Conference Proceeding
• Language: English
• Subjects: Degradation; Hot carriers; Operating Life Test; Performance evaluation; Power Amplifier; Power amplifiers; Radio frequency; RF CMOS reliability; Robustness; Semiconductor device modeling
• ISSN: 1938-1891
• DOI: 10.1109/IRPS48228.2024.10529364

RF reliability of a power amplifier is analyzed for automotive applications. Autonomous driving detection based on radar sensors require a high level of reliability to perform the mission during the operative lifetime. The robustness of power amplifier under RF stress is presented in the paper. After introduction of the receiver/transmitter components and phase modulation scheme used in radar sensor, a first analysis is performed at device level to figure out the reliability capability to sustain aggressive voltage profile. Using a 77GHz vectorial load-pull tester, several stresses are carried out to exacerbate the degradation of a LVT NMOS in 28nm FD-SOI technology, used as a power stage. With special tuning of the biasing point, input and output matching networks and input power, is it possible to generate voltage profile that mimics a load-line of class-AB power amplifier, or a RF voltage profile centered in the worst-case hot carrier DC condition, i.e. \mathbf{V}_{\mathbf{DS}} close to \mathbf{V}_{\mathbf{GS}} . Results show small degradation for these two RF profiles. Then, in the second part, Operating Life Test is performed at 77GHz with a dedicated test chip where RF signal is build-in and output amplified power is measured with a power meter. Characterization of the output power is performed both in the on-wafer and the on-board version. The result of 1500h burn-in for several parts is presented. The degradation magnitude during the stress is in agreement with simulation.