Low frequency noise spectroscopy for Schottky contacts

In this paper, we show that low-frequency noise observed in semiconductor devices, in particular Schottky diodes, can be utilized to analyze spectroscopically the distribution of the traps involved and thereby to diagnose specific structures and process conditions. All the possible known mechanisms for low-frequency noise, namely, mobility and diffusivity fluctuation, thermal activation, tunneling and random walk of electrons through bulk and/or interface trap states, are critically reviewed and compared. Also, experimental results are analyzed to give useful information on the trap distribution and the effect of process conditions on the device characteristics. Use of low-frequency noise measurements as a spectroscopy tool complementary to other conventional methods is emphasized.