Date of Graduation

5-2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Engineering (PhD)

Degree Level

Graduate

Department

Electrical Engineering

Advisor/Mentor

H. Alan Mantooth

Committee Member

Juan Balda

Second Committee Member

Simon Ang

Third Committee Member

Roy McCann

Fourth Committee Member

Guofu Niu

Keywords

Applied sciences, Device characterization, Low-voltage circuits, MOSFETs, Semiconductors, Silicon carbide

Abstract

The integration of low voltage and high voltage circuits on SiC has profound applications. SiC power devices have proved their superiority in terms of high temperature operation, faster switching frequencies and larger power densities when compared with Si power devices. The control of SiC power devices however, lies in the hands of low voltage circuits built on Si. Thus, there exists a separation in the overall system between the low voltage and high voltage side, which increases system cost, weight and reduces efficiency. With the advancement in low voltage SiC processing technology, low voltage control circuits can be made on the same die as power devices, and power systems will become compact, robust and more efficient. A new low voltage process in 4H-SiC has been characterized and modeled. In order to design circuits with the low voltage process, designers need accurate device models for simulation. Currently, there exist no compact models in the public domain for low voltage SiC MOSFETs. This work aims at filling that void, by providing a modified PSP model for SiC MOSFETs. In addition, a new compact model for SiC power MOSFETs has also been developed and validated with characterization data from a commercially available 1200 V, 20 A power MOSFET. A gate driver chip has been designed and fabricated in 4H-SiC using the developed models. The gate driver chip will drive commercially available power MOSFETs in an integrated AC/DC converter application.

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