Effect of Neutron Irradiation on High Voltage 4H-SiC Vertical JFET Characteristics: Characterization and Modeling

Author

Popelka, S. ; Hazdra, Pavel ; Sharma, Ritu ; Zahlava, V. ; Vobecky, J.

Author_Institution

Dept. of Microelectron., Czech Tech. Univ. in Prague, Prague, Czech Republic

Volume

61

Issue

6

fYear

2014

fDate

Dec. 2014

Firstpage

3030

Lastpage

3036

Abstract

The effect of neutron irradiation on commercial vertical high voltage normally-OFF SiC power N-JFETs was investigated. JFETs were irradiated with 1 MeV neutron equivalent fluences up to 4×10¹⁴ cm^-2. Measurement showed that fast neutrons introduce deep levels acting mostly as deep acceptor centers. These centers gradually compensate lightly doped channel and drift regions of JFETs. As a result, characteristics are deteriorated, the JFET threshold voltage gradually increases and transconductance is lowered. At fluences higher than 4×10¹⁴ cm^-2, the low doped n-regions are fully compensated and transistor loses its functionality. The 2D physical model of JFET in ATLAS simulator was developed and calibrated including the neutron irradiation effects. Simulation showed a good agreement with experimental data. This confirmed that carrier removal in the channel and drift region by acceptors centers introduced by neutrons is a dominant reason of SiC JFET degradation.

Keywords

deep levels; doping; junction gate field effect transistors; neutron activation analysis; neutron flux; semiconductor device models; silicon compounds; wide band gap semiconductors; ATLAS simulator; JFET degradation; SiC; carrier removal; deep acceptor center; deep level; drift region; electron volt energy 1 MeV; high voltage 4H-silicon carbide vertical JFET characteristic; junction gate field-effect transistor; lightly doped channel; low doped n-region; neutron equivalent fluence; neutron irradiation effect; threshold voltage; transconductance; vertical high voltage normally-off power N-JFET; Doping; JFETs; Neutrons; Radiation effects; Silicon carbide; Junction field effect transistor (JFET); neutrons; radiation effects; silicon carbide (SiC);

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/TNS.2014.2358957

Filename

6935041