Effect of 50 MeV Li3+ ion irradiation on electrical characteristics of high speed NPN power transistor

✍ Scribed by C.M. Dinesh; Ramani; M.C. Radhakrishna; R.N. Dutt; S.A. Khan; D. Kanjilal

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 192 KB
• Volume: 266
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2008.02.048

✦ Synopsis

Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50 MeV Li 3+ ion irradiation in the fluence range 1 Â 10 11 -1.8 Â 10 12 ions cm À2 on NPN power transistor. The range (R), electronic energy loss (S e ), nuclear energy loss (S n ), total ionizing dose (TID) and total displacement damage (D d ) in the silicon target are calculated from TRIM Monte Carlo Code. Output resistance is 3.568 Â 10 4 X for unirradiated device and it increases to 6 Â 10 7 X as the fluence is increased from 1 Â 10 11 to 1.8 Â 10 12 ions cm À2 . The capacitance of the emitter-base junction of the transistor decreases and dielectric loss of the emitter-base junction increases with increase in ion fluence. The built in voltage of the unirradiated sample is 0.5 V and it shifts to 0.4 V after irradiation at fluence of 1.8 Â 10 12 ions cm À2 and the corresponding doping density reduced to 5.758 Â 10 16 cm À3 . The charge carrier removal rate varies linearly with the increase in ion fluence.