Interface quality study of ECR-deposited and rapid thermal annealed silicon nitride Al/SiNx:H/InP and Al/SiNx:H/In0.53Ga0.47As structures by DLTS and conductance transient techniques

Abstract

In this article, we study the influences of the rapid thermal annealing temperature and dielectric composition on the electrical characteristics of ECR-deposited silicon nitride SiNx:H–InP and SiNx:H–InGaAs interfaces. C–V, deep level transient spectroscopy (DLTS) and conductance transient analysis have been applied. As for InP cases, DLTS results reveal that rapid thermal annealing application increases interfacial state density. In contrast, transient conductance measurements show that disorder induced gap-state (DIGS) damage density diminishes when RTA is applied. So, we can conclude that RTA treatments take out the insulator damage to the interface. In the InGaAs-n cases, we have observed that DIGS damage evolution with RTA temperature is opposite to the interfacial state density. This behaviour seems to suggest some temperature activated defect exchange between the insulator and the interface. Finally, as for the insulator composition influence on the interface quality of the InGaAs-n samples, DLTS results suggest that the intermediate x values (1.43 and 1.50) provide better interfaces than extreme x values. Conductance transient measurements add complementary information: insulator damage increases when x increases. Hence, x=1.43 seems to be the best choice to improve the overall interface quality.