Monitoring plasma nitridation of HfSiOx by corona charge measurements

In this work we present an evaluation and understanding of corona charge measurements on decoupled plasma nitrided (DPN) HfSiOx. Typical corona charge parameters such as equivalent oxide thickness (EOT), density of interface states (Dit) and saturated surface voltage (Vsat) are evaluated. It is shown that especially Dit and Vsat are promising parameters for nitiridation monitoring as they show correlation to DPN parameters within good accuracy. Fundamental explanation is given for the observed behaviour of Vsat by use of a direct tunneling model.