Chin. Phys., 2003, Vol. 12(1): 89-93    DOI: 10.1088/1009-1963/12/1/016
 CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES Prev   Next

# Theoretical investigation of incomplete ionization of dopants in uniform and ion-implanted 4H-SiC MESFETs

Wang Shou-Guo, Zhang Yi-Men, Zhang Yu-Ming
Institute of Microelectronics, Xidian University, Xi'an 710071, China
Abstract  The effects of incomplete ionization of nitrogen in 4H-SiC have been investigated. Poisson's equation is numerically analysed by considering the effects of Poole--Frenkel, and the effects of the potential on $N^+_\dd$ (the concentration of ionized donors) and $n$ (the concentration of electrons). The pinch-off voltages of the uniform and the ion-implanted channels of 4H-SiC metal-semiconductor field-effect transistors (MESFETs) and the capacitance of the gate are given at different temperatures. Both the Poole--Frenkel effect and the potential have influence on the pinch-off voltage $V_{\rm p}$ of 4H-SiC MESFETs. Although the $C$-$V$ characteristics of the ion-implanted and the uniform channel of 4H-SiC MESFETs have a clear distinction, the effects of incomplete ionization on the $C$-$V$ characteristics are not significant.
Received:  19 April 2002      Published:  20 January 2003
 PACS: 85.30.Tv (Field effect devices) 85.40.Ry (Impurity doping, diffusion and ion implantation technology) 72.20.Ht (High-field and nonlinear effects)
Fund: Project supported by the National Defence Pre-Research Foundation of China (Grant No 8.1.7.3).