Avalanche Injection of Electrons into Insulating SiO2 Using MOS Structures

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Abstract
A model is presented to explain the direct current which flows when a metal‐SiO2–Si (MOS) capacitor is driven by a large‐amplitude ac signal sufficient to produce avalanche breakdown in the silicon. During the portion of each cycle that the silicon is in avalanche breakdown, minority carriers generated by impact ionization are accelerated towards the interface. It is assumed that some of these minority carriers attain sufficient energy to surmount the potential barrier at the interface, enter the SiO2, and result in a dc component of current. Experimental results from MOS structures with p‐type silicon substrates (electron injection into the SiO2) are shown to be consistent with this model. If the energy distribution of hot electrons in the Si avalanche plasma is Maxwellian, the data indicate that the effective temperature is 5550°K.