Title :
Radiation dependence of inverter propagation delay from timing sampler measurements
Author :
Buehler, M.G. ; Blaes, B.R. ; Lin, Y.S.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
fDate :
12/1/1989 12:00:00 AM
Abstract :
A timing sampler consisting of 14 four-stage inverter-pair chains with different load capacitances was fabricated in 1.6-μm n-well CMOS and irradiated with cobalt-60 at 10 rad(Si)/s. For this CMOS process the measured results indicate that the rising delay increases by about 2.2 ns/Mrad(Si) and the falling delay increase is very small, i.e., less than 300 ps/Mrad(Si). The amount of radiation-induced delay depends on the size of the load capacitance. The maximum value observed for this effect was 5.65 ns/pF-Mrad(Si). Using a sensitivity analysis, the sensitivity of the rising delay to radiation can be explained by a simple timing model and the radiation sensitivity of DC MOSFET parameters. This same approach could not explain the insensitivity of the falling delay to radiation. This may be due to a failure of the timing model and/or trapping effects
Keywords :
CMOS integrated circuits; X-ray effects; delays; insulated gate field effect transistors; integrated circuit testing; logic gates; semiconductor device models; timing circuits; 1.6 micron; CMOS process; DC MOSFET parameters; X-rays; annealing; falling delay; inverter propagation delay; load capacitance; radiation sensitivity; radiation-induced delay; rising delay; sensitivity analysis; timing model; timing sampler; trapping effects; CMOS technology; Cobalt; Inverters; MOSFET circuits; Propagation delay; Radiation detectors; Ring oscillators; Semiconductor device measurement; Semiconductor device modeling; Timing;
Journal_Title :
Nuclear Science, IEEE Transactions on
