Single-grain Si thin-film transistors SPICE model, analog and RF circuit applications

Abstract

Single-grain thin-film transistors (SG-TFTs) fabricated inside location-controlled using μ-Czochralski process exhibit SOI-FETs like performance despite processing temperatures remaining below 350°C. Thus, the SG-TFT is a potential technology for large-area highly-integrated electronic system and system-in-package, taking advantage of the system-on-flexible substrate and low manufacturing cost capabalities. The SG-TFT is modeled based on the BSIMSOI SPICE model where the mobility parameter is modified to fit the SG-TFT behavior. Therefore, analog and RF circuits can be designed and benchmarked. A two-stage telescopic cascode operational amplifier fabricated in a prototype 1.5μm SG-TFT technology demonstrates DC gain of 55dB and unity-gain bandwidth of 6.3MHz. A prototype CMOS voltage reference demonstrates a power supply rejection ratio (PSRR) of 50dB. With unity-gain frequency, fT, in the GHz range, the SG-TFT can also enable RF circuits for wireless applications. A 12dB gain RF cascode amplifier with integrated on-chip inductors operating in the 433MHz ISM band is demonstrated.