Effects of deposition temperature on the oxidation resistance and electrical characteristics of silicon nitride

A study was made of the effects of deposition temperature on the oxidation resistance and electrical characteristics of silicon nitride. It was found that silicon nitride below a certain limit thickness has no oxidation resistance. This threshold falls as the deposition temperature is lowered. 3-nm-thick silicon nitride deposited at 600/spl deg/C has sufficient oxidation resistance For wet oxidation at 850/spl deg/C, while 5 nm film deposited at 750/spl deg/C has no oxidation resistance. The electrical characteristics also improve as the deposition temperature is lowered. 6-nm-thick silicon nitride deposited at 600/spl deg/C shows a TDDB lifetime that is about two orders longer than that of 6-nm-thick silicon nitride deposited at 700/spl deg/C. It was also found that the silicon nitride transition layer which is deposited at the initial stage of deposition influences the oxidation resistance and electrical characteristics of thin silicon nitride. It was concluded that lowering the deposition temperature reduces the influence of the transition layer and improves the oxidation resistance and electrical characteristics of thin silicon nitride.<
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