Temperature dependence of low-frequency noise in n-channel MOS transistors

Abstract

Monitoring of the time sequence and frequency spectrum of a random noise in the MOS transistor reveals that the low-frequency noise in this device is due to the superposition of individual capture or emission events at the silicon-oxide interface or in the bulk of the gate-oxide. In addition, the noise level of the MOS device is found to fluctuate greatly with temperature in the range of 77–375 K. In a noise amplitude versus temperature plot, valleys and peaks are observed at certain temperatures, and their locations seem to convey some special information. Moreover, the spectral slope is found to possess the same temperature dependence as the amplitude, which implies that these two quantities could be governed by the same physical mechanisms. On the other hand, result also suggests that the temperature dependence of the noise is strongly governed by the gate-oxide preparation techniques.