A novel method to characterize MOS transistors with mixed gate dielectric technologies

Abstract

The authors have developed an extraction technique suitable for studying mixed dielectric systems in MOS transistors. The method gives accurate modeling parameters for low-field mobility and surface roughness scattering, and it removes the dependence of gate dielectric capacitance on the results. The technique has been implemented in interpretive BASIC written on a desk-top HP9000 computer, and the program is easily adapted to other automated data acquisition systems since advanced numerical methods are not necessary. A set of I/sub DS/-V/sub GS/ measurements taken at different bulk biases is required, along with the value of effective gate capacitance. The usefulness of this extraction method is demonstrated by application to ONO and pure oxide gate dielectric transistors of differing compositions and thicknesses. The utility of this method lies in the ease of implementation, and the ability to remove the gate dielectric capacitance in extracting accurate modeling parameters. >