Title :
Random telegraph signals in small MOSFETs after X-ray irradiation
Author :
Muto, Hirotaka ; Tsai, Ming-Horn ; Ma, Tso-Ping
Author_Institution :
Dept. of Electr. Eng., Yale Univ., New Haven, CT, USA
fDate :
12/1/1991 12:00:00 AM
Abstract :
The random telegraph signals (RTSs) in small MOSFETs before and after X-ray irradiation and after annealing have been studied. It is believed that the RTSs arise from the trapping/detrapping of individual defect(s) near the SiO2/Si interface. The key results from this study are: (1) RTSs existed prior to X-ray irradiation in both weak inversion and strong inversion due to process-induced defects, (2) X-ray irradiation causes the disappearance of the original RTS and the appearance of new RTS with different emission time constants, (3) X-ray irradiation also causes high frequency current fluctuations with much more irregular amplitude distribution than the slower RTSs, (4) annealing at 200-300°C in nitrogen removes most of the high frequency component and reveals more clearly some of the radiation-induced RTSs, and (5) annealing at 400°C essentially removes all of the radiation-induced RTSs, but causes the reappearance of one set of the original RTS traces in strong inversion
Keywords :
X-ray effects; annealing; current fluctuations; electron device noise; insulated gate field effect transistors; interface electron states; random noise; semiconductor device testing; 200 to 400 degC; N2; SiO2-Si interface; X-ray irradiation; annealing; defect trapping; emission time constants; high frequency current fluctuations; interface traps; random telegraph signals; small MOSFETs; strong inversion; weak inversion; Annealing; Electron emission; Electron traps; Fluctuations; Frequency; MOSFETs; Microelectronics; Microscopy; Telegraphy; Voltage;
Journal_Title :
Nuclear Science, IEEE Transactions on
