INVESTIGATION OF RADIATION HARDENED CIRCUIT ELEMENTS,
Abstract
An investigation was made of hardened insulated-gate field effect devices. Included are a review of MOS transistor theory, a derivation of MOS characteristics as a function of substrate bias, and the early results in the fabrication of complementary enhancement pairs. These devices, made in Czochralski silicon 3 microns thick, are fabricated by processes compatible with normal MOS integrated circuit procedures. The early pairs have poorly matched thresholds and low transconductance on the N-enhancement devices. Breakdown voltages were in excess of 40 volts for both P and N devices. The P device has characteristics like discrete P-enhancement devices. A blocking diffusion is used to provide a barrier to surface inversion in the N device without increasing device junction areas. Dielectrically isolated MOS integrated circuits can offer significant advantages in certain circuit applications. The major advantage accrues due to individually biased substrate regions for each active device. This allows certain simplifications in MOS circuit designs expanding the range of operation and optimizing gain characteristics. For this reason, a theory of MOS operation as a function of substrate bias was derived and is presented in this report. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 1967
- Accession Number
- AD0664922
Entities
People
- D. A. Mcwilliams
- L. C. Davis