Role of atomic variability in dielectric charging: A first-principles-based multiscale modeling study

Ravi Pramod Kumar Vedula, Purdue University
Sambit Palit, Purdue University
Muhammad A. Alam, Purdue University
Alejandro Strachan, Birck Nanotechnology Center and Purdue University

Abstract

We present a dielectric charging model that combinesab initiocalculations of trap levels with a continuum-level transport model and apply it to interpret charging currents in amorphous silicon nitride. Density functional theory calculations on an ensemble of structures predict a distribution of electron trap levels up to 1.8 eV below the conduction band edge and provide insight into the physical trapping mechanisms. Incorporating this information in the continuum model, as opposed to the standard approach of a single adjustable trap level, not only leads to a more accurate description of experimental current transients in metal-insulator-metal capacitors, but also to a more precise and physical determination of associated material properties such as metal-dielectric barrier height.

Discipline(s)

Electronic Devices and Semiconductor Manufacturing