The Influence of Surface Pit Shape on 4H-SiC MOSFETs Reliability under High Temperature Bias Tests

Kosuke Uchida; Toru Hiyoshi; Taro Nishiguchi; Hirofumi Yamamoto; Shinji Matsukawa; Masaki Furumai; Yasuki Mikamura

doi:10.4028/www.scientific.net/MSF.858.840

Paper Titles

Potential of 4H-SiC CMOS for High Temperature Applications Using Advanced Lateral p-MOSFETs
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Analytical Description of the Input Capacitance of 4H-SiC DMOSFET’s in Presence of Oxide-Semiconductor Interface Traps
p.825

Characteristics of High-Threshold-Voltage Low-Loss 4H-SiC MOSFETs with Improved MOS Cell Structure
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Comparison of Test Methods for Proper Characterization of V_T in SiC MOSFETs
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The Influence of Surface Pit Shape on 4H-SiC MOSFETs Reliability under High Temperature Bias Tests
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Si/SiC Substrates for the Implementation of Linear-Doped Power LDMOS Studied with Device Simulation
p.844

Trench-MOSFETs on 4H-SiC
p.848

SiC Power Switches Evaluation for Space Applications Requirements
p.852

Effect of Electron Irradiation on 1700V 4H-SiC MOSFET Characteristics
p.856

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The Influence of Surface Pit Shape on 4H-SiC MOSFETs Reliability under High Temperature Bias Tests

Abstract:

The influence of surface pit shape on 4H-SiC double implanted MOSFETs (DMOSFETs) reliability under a high temperature drain bias test has been investigated. Threading dislocations formed two types of pit shapes (deep pit and shallow pit) on an epitaxial layer surface. The cause of the failure was revealed to be an oxide breakdown above the pit generated at the threading mixed dislocation in both pit shapes. Weibull distributions between two types of pits were different. Although the DMOSFETs on the epitaxial layer with the deep pit show longer lifetime than those with the shallow pit, the epitaxial layer with the shallow pit is suitable to estimate the lifetime of the DMOSFETs because of a linearity of the Weibull plot. The lifetime of the DMOSFETs with the shallow pit was dominated by an oxide electric field. The maximum oxide electric field required to obtain the lifetime of more than 10 years was estimated to be 2.7 MV/cm.