Calculation of occupied and unoccupied surface state density of silicon in MOSFET using surface photovoltage (SPV) transient measurement

Abstract

The densities of occupied and unoccupied surface state in silicon inside MOSFET were determined from the SPV versus time plots. This was done by illuminating the sample with a single light wavelength corresponding to the energy position of the surface state under consideration. The surface photovoltage transient quantities were used in the calculation of the surface state parameters under consideration. The obtained result, which are of the order 10¹¹ − 10¹³ cm⁻², are comparable to those previously reported that utilizes real silicon surface (a free silicon wafer) using the Kelvin probe method and thus, the MOS structure of MOSFETs can be used as an alternative method for studying electronic properties of semiconductors particularly silicon.