A voltage reference circuit with 3 V output has been designed and implemented in an SOI FD (fully-depleted) CMOS technology for very wide temperature range applications. The design uses lateral bipolar transistors and thin-film diffusion resistors. The circuit has been fabricated and tested over the full operating temperature range (25°C-300°C) and provides a temperature coefficient better than 100 ppm/°C.
Adriaensen, S., Dessard, V., & Flandre, D. (1999). A bandgap circuit operating up to 300°C using lateral bipolar transistors in thin-film CMOS-SOI technology. Proceedings of HITEN 1999, 49-52. https://hdl.handle.net/2078.5/252688