A precision noise measurement and analysis method used to estimate reliability of semiconductor devices

In this paper, some problems with previous ultra-low noise measurement methods have been discussed, then a double-channel preamplifier cross-spectrum measurement method has been adopted, different from the previous cross-correlation method [A. van der Ziel, Noise: Sources, Characterization, Measurement, p. 54. Prentice-Hall, Englewood Cliffs, NJ (1970), L. Stor, Experimental techniques in noise measurement with special emphasis on precision measurement, Proc. 10th Int. Conf: on Noise in Physical Systems, pp. 551-560. Budapest, Hungary (1989)] in that an average periodogram using a windowing procedure has been performed. The theoretical analysis shows that the expected value of the cross-spectrum is incoherent with background noise and zero-drift from the preamplifier and power supply system, the average periodogram can decrease the variance of the periodogram and the additional bias of the cross-spectrum periodogram. Experimental results demonstrate that if the equivalent input noise of measuremental set-up is two orders of magnitude lower than the noise of each preamplifier, then an ultra low noise spectrum can be measured accurately, the low limit is about 0.1 nV/root Hz at 1 kHz, which is 20 dB lower than the noise of each preamplifier. The thermal noise of a small resistance and the shot noise of a diode under forward conditions have been measured, the experimental results are in good agreement with the theoretical value, this means that this method is feasible and accurate for an ultra-low noise spectrum measurement. Finally, the noise spectrum analysis procedure based on the curve fitting method has been presented, which ensures that we obtain an accuracy value of three noise components in the semiconductor, i.e. 1/f noise, white noise and g-r noise. This noise spectrum analysis method is a useful tool for investigation of noise mechanism, the diagnosis of defects in semiconductors and reliability estimation. (C) 1997 Elsevier Science Ltd.