Subthreshold Technique for Fixed and Interface Trapped Charge Separation in Irradiated MOSFETs

This guideline document covers the use of the subthreshold charge separation technique for analysis of ionizing degradation of gate dielectrics in MOSFETs and isolation oxide degradation in parasitic FETs. The subthreshold technique is used to separate radiation induced threshold voltage shifts into voltage shifts due to oxide trapped holes and interface states. The theory and assumptions of this technique are discussed in detail. The application is discussed with respect to electrical measurements and data analysis. Limitations in the application with regard to interferences from leakage and violations of assumptions are presented. In the appendix, a proposed measurement and data analysis standard is given.