Radiation-induced off-state leakage current in commercial power MOSFETs

The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO/sub 2/) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

[1]  T. A. Hill,et al.  Identification of radiation-induced parasitic leakage paths using light emission microscopy , 2003, Proceedings of the 7th European Conference on Radiation and Its Effects on Components and Systems, 2003. RADECS 2003..

[2]  C. R. Wie,et al.  Study of radiation effects in /spl gamma/-ray irradiated power VDMOSFET by DCIV technique , 2001 .

[3]  The surface generation hump in irradiated power MOSFETs , 1994 .

[4]  Kenneth F. Galloway,et al.  SEGR and SEB in n-channel power MOSFETs , 1996 .

[5]  B. J. Baliga,et al.  Modern Power Devices , 1987 .

[6]  R. L. Pease,et al.  Influence of ion beam energy on SEGR failure thresholds of vertical power MOSFETs , 1996 .

[7]  Determining the drain doping in DMOS transistors using the hump in the leakage current , 1994 .

[8]  P. Winokur,et al.  Simple technique for separating the effects of interface traps and trapped‐oxide charge in metal‐oxide‐semiconductor transistors , 1986 .

[9]  R.,et al.  Challenges in hardening technologies using shallow-trench isolation , 1998 .

[10]  Theodore I. Kamins,et al.  Device Electronics for Integrated Circuits , 1977 .

[11]  Daniel M. Fleetwood,et al.  Charge yield for cobalt-60 and 10-keV X-ray irradiations of MOS devices , 1991 .

[12]  P. S. Winokur,et al.  Interface-State Generation in Radiation-Hard Oxides , 1980, IEEE Transactions on Nuclear Science.

[13]  T. A. Hill,et al.  Identification of radiation-induced parasitic leakage paths using light emission microscopy , 2003, IEEE Transactions on Nuclear Science.