DocumentCode :
1118174
Title :
High dI/dT light-triggered thyristors
Author :
Przybysz, John X. ; Miller, Donald L. ; Leslie, Scott G. ; Kao, Yu C.
Author_Institution :
Westinghouse Research and Development Center, Pittsburgh, PA
Volume :
34
Issue :
10
fYear :
1987
fDate :
10/1/1987 12:00:00 AM
Firstpage :
2192
Lastpage :
2199
Abstract :
Directly light-triggered, 4000- and 6000-V thyristors were designed, fabricated, and tested to obtain high performance in dI/dt, dV/dt, and photosensitivity. Built-in resistors protected both auxiliary stages during high dI/dt turn-on. The novel use of etched moats to define the resistors was compatible with an optical gate structure that gives high dV/dt and good photosensitivity. No additional processing steps were needed to fabricate these devices, as compared to standard light-triggered thyristors. A record value of 1000 A/µs at 60 Hz was measured on a 6000-V thyristor, and 850 A/µs was safely triggered with only 1.8 mW of light. The dV/dt immunity of the photogate structure measured 4000 V/µs, rising exponentially to 80 percent of 4000 V, VDRM. Thyristors triggered by dV/dt were not destroyed. A new model of resistor heating was combined with the first measurements of the current pulses through both built-in resistors to identify the mechanism responsible for occasional burn-out of the second resistor. The failure mechanism was conductivity modulation in the surface of the resistor during its microsecond on-time caused by thermally generated carriers. The test results confirmed the utility of built-in resistors for high dI/dt performance with minimal light power and for nondestructive dV/dt triggering.
Keywords :
Current measurement; Etching; Heating; Immunity testing; Optical recording; Protection; Pulse measurements; Resistors; Thermal conductivity; Thyristors;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/T-ED.1987.23216
Filename :
1486927
Link To Document :
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