Reliability Studies of Fully Integrated CMOS Power Amplifier on Thinned Substrate for Flexible Electronics

This paper presents reliability studies of CMOS Radio Frequency Integrated Circuits (RFICs) on thinned silicon substrates for next-generation flexible and wearable electronics. As a test case, a fully integrated power amplifier (PA) with various die-substrate thicknesses was chosen. The PA under study was designed and fabricated using 180 nm CMOS process. Performances of the PA chips were characterized, and results are compared before and after die thinning from 250 µm to 50 µm and 35 µm, respectively. All the dies were placed face-up for probing on the top of a metal chuck with ground connection inside the micro-chamber of a probe station. For brevity, only the s-parameters of the PA chips were measured and analyzed.