Increased resistance in p-type poly-Si resistors by thermal anneal reduction interface charge

The effect of thermal annealing on characteristics of p-type poly-Si thin-film resistors was investigated. A significant increase was observed as the source/drain anneal temperature or anneal time was increased. The increased resistance is due to a reduction in current component arising from field-enhanced current via grain-boundary trap states at the drain end of the resistor. The reduction is this field-enhanced current arises primarily from a reduction of positive charge density at the top and bottom oxide/poly-Si interfaces of the thin-film resistor (and thus a reduction in the magnitude of the drain electric field) with increased annealing temperature and time.<
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