Characteristics and mechanism of 1/f noise in GaAs Schottky barrier field-effect transistors

Measurements of the absolute spectral density of 1/f noise in GaAs Schottky barrier field-effect transistors (MESFET’s) show that 1/f noise consists of a surface component and a separable uncorrelated bulk component. The surface component is caused by trapping of electrons by surface states. The bulk component is correlated with the low field electron mobility and deep level trap concentration versus depletion depth profiles and can only be explained by the random fluctuations in the occupancy of deep level traps in the depletion region. A simple model quantitatively explains the observed characteristics of the bulk component of the noise at a low drain voltage. At normal operating drain voltages the observed 1/f noise characteristics are consistent with the model.