Application of 1/f noise to the inspection of defects in electron devices

摘要

1/f noise has a power-spectrum that is inversely proportional to frequency. 1/f noise generated in semiconductors was considered and the formula of the sensitivity of 1/f noise was obtained. According to the formula, the mean square value of 1/f noise was increased by the fourth power of current density. Because of this high sensitivity to the current concentration, 1/f noise is available to detect device faults. Then photoconductive cells were examined and the faults were found from the 1/f noise curve. 1/f noise of carbon potentiometers was measured in gas corrosion tests of flowing sulfa-dioxide. The change of 1/f noise value after being exposed to gas was about 60 times larger than that of the resistance value. It showed that 1/f noise was available for finding out the defects in electron devices.