Analysis of band-to-band tunneling leakage current in trench-capacitor DRAM cells

Evidence demonstrating that the band-to-band tunneling leakage current occurs mainly at the edge of the self-aligned isolation rather than the trench upper corners is presented. Moreover, the leakage current increases drastically with the decrease of capacitor oxide thickness. It is shown that the leakage current limits the thickness of capacitor oxide to more than 80 AA even if the operation voltage is reduced to 3.3 V from 5 V.<
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