LOW-FREQUENCY NOISE SPECTROSCOPY

Electrical noise in excess of thermal and shot noise is caused by impe rfections in the device. Its control can improve the quality of the de vice and its measurement can give considerable information about the n ature of the defects involved. For defects with discrete energy distri butions spectroscopy can be used to identify the defect and measure it s properties. Excess noise has large intensity at low frequencies and several mechanisms can be identified. The value of the technique for m any systems is described. Comparison is made with other methods of stu dying such defects.