Comparative measurements of the electron emission behavior of Si3N4-InGaAs interfaces prepared by remote and direct PECVD

Abstract

The effects on the insulator-semiconductor interface of two different deposition methods of silicon nitride on In0.53Ga0.47As have been electronically studied using capacitance-voltage (CV) and deep level transient spectroscopy (DLTS) measurements. The CV data showed very similar behavior on both types of sample, but the DLTS results were surprisingly different. The behavior of samples fabricated using direct plasma enhanced chemical vapor deposition (PECVD) can be explained by electronic emission from interface states to the conduction band minimum. However, the remote PECVD method gave a DLTS peak corresponding to electron emission with a low activation energy ≈0.13 eV. As with the direct PECVD samples, the thermal activation energy decreased as the bias was made more positive, but in this case the change in emission energy was only a fraction of the shift in the Fermi level position. A model is proposed involving the concepts of lattice relaxation and hole capture to explain this behavior.