Theoretical and experimental determination of deep trap profiles in semiconductors

A simple and accurate expression is developed for profiling deep-level traps in semiconductors using Schottky barriers and deep-level transient spectroscopy (DLTS). Through the use of computer simulations as well as the application to actual experimental results it is shown that the standard expressions which are generally employed can result in large errors in the calculated trap concentration near the metal semiconductor interface. It is also pointed out that the standard DLTS expressions will result in large differences in the calculated trap concentrations for donorlike or acceptorlike traps when the trap concentration is comparable to the shallow level concentration.