IMPACT IONIZATION IN SILICON - A REVIEW AND UPDATE

After defining the multiplication factor and the ionization rate together with their interrelationship, multiplication and breakdown models for diodes and MOS transistors are discussed. Different ionization models are compared and test structures are discussed for measuring the multiplication factor accurately enough for reliable extraction of the ionization rates. Multiplication measurements at different temperatures are performed on a bipolar NPN transistor, and yield new electron ionization rates at relatively low electrical fields. An explanation for the spread of the experimental values of the existing data on ionization rate is given. A new implementation method for a local avalanche model into a device simulator is presented. The results are less sensitive to the chosen grid size than the ones obtained from the existing method. © 1990.