WEAK FLUENCE DEPENDENCE OF CHARGE GENERATION IN ULTRA-THIN OXIDES ON SILICON

We examined charge generation in metal/tunnel-oxide/n-silicon diodes f abricated with polycrystalline silicon (poly-Si) gates. In these devic es, electron injection from the substrate in the direct tunnel regime leads to charge generation which evolves with time rather than electro n fluence, as has been previously reported for injection in the Fowler -Nordheim tunnel regime. Our findings complete the picture proving the existence of a distinct degradation mode in the direct tunnel regime for devices fabricated at different facilities, using both aluminum an d polycrystalline silicon gates, and stressed via either gate or subst rate injection. This work directly impacts the prediction of the lifet imes of devices in which direct tunneling is measurable.