High Temperature Compensated Voltage Reference Integrated Circuits on 4H-SiC Material

摘要

This work demonstrates a functional fabricated high temperature compensated Voltage Reference (VR) integrated circuit on 4H-SiC material. The study starts with an experimental analysis on the feasibility on silicon carbide (SiC) of the widely used bandgap reference concept both with Schottky and bipolar diodes. Then an original solution is proposed for a special finger type MESFET. Our approach of the MESFET design overcomes the typical embedded drain leakage of finger type MESFET. This device design was specially developed for using in analog schematics on SiC. Further, an original VR schematic is proposed avoiding the bandgap reference topology and accordingly avoiding an operational amplifier (OpAmp), which is not yet developed on SiC. The performed measurements on the fabricated integrated circuits show a temperature coefficient (TC) comparable to the normal bandgap voltage references on silicon but this SiC circuit is able to work up to 300 degrees C, compared to 125 degrees C for silicon or 200 degrees C for SOI (silicon on insulator). A very important progress of our work is the integration of the presented circuit on the same SiC chip with a power lateral MESFET. Additionally, the circuit contains a linear temperature sensor useful for over temperature protection.