Title :
Gate field emission induced breakdown in power SiC MESFETs
Author :
Cha, Ho-Young ; Thomas, C.I. ; Choi, Y.C. ; Eastman, Lester F. ; Spencer, Michael G.
Author_Institution :
Dept. of Electr. & Comput. Eng., Cornell Univ., Ithaca, NY, USA
Abstract :
The breakdown mechanism of SiC MESFETs has been analyzed by careful investigation of gate leakage current characteristics. It is proposed that gate current-induced avalanche breakdown, rather than drain avalanche breakdown, is the dominant failure mechanism for SiC MESFETs: thermionic-field emission and field emission are dominant for the ON state (above pinch-off voltage) and the OFF state (below pinch-off voltage), respectively. The effect of Si/sub 3/N/sub 4/ passivation on breakdown voltage has been also investigated. Si/sub 3/N/sub 4/ passivation decreases the breakdown voltage due to higher electric field at the gate edge compared to edge fields before passivation. A reduction in surface trapping effects after passivation results in the higher electric field because the depletion region formed by trapped electrons is reduced significantly.
Keywords :
avalanche breakdown; electron field emission; leakage currents; passivation; power MESFET; semiconductor device breakdown; silicon compounds; thermionic electron emission; wide band gap semiconductors; Si/sub 3/N/sub 4/; Si/sub 3/N/sub 4/ passivation; SiC; SiC power MESFET; breakdown voltage; failure mechanism; gate current-induced avalanche breakdown; gate field emission-induced breakdown; gate leakage current; pinch-off voltage; surface trapping; thermionic-field emission; Avalanche breakdown; Breakdown voltage; Electric breakdown; Electron traps; Failure analysis; Leakage current; MESFETs; Passivation; Silicon carbide; Thermionic emission;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.815422
