关键词: 栅氧化, 总剂量电离效应, 阈值电压漂移ΔVtn

Abstract: The radiation ionization of total dose(TID)of the LV/HVNMOS based on the CMOS standard process has been analysed.For the LVNMOS witch the gate oxide thickness less than 12.5 nm,it is found that the dryandwetoxidationmethodshave little effect about the threshold voltage drift(ΔVtn)due to the TID effect.Under the condition of 500 krad(Si),the ΔVtnof the device prepared by the wet-oxidation process is 0.025 V less thanthe device thatpreparedbydry-oxidationprocess.For the HVNMOS device which the gate oxide thickness was 26 nm,the effect of the oxidation process and the oxidation temperature due to the TID was significant.Under the condition of 500K rad(Si),the threshold voltage drift(ΔVtn)due to the TID effect which prepared by the dry-oxidation process(900℃)was about 3 times higher than the wet-oxidation process.The superiority of the TID effect ΔVtn is mainly attributed to the charge transfer effect of SiO2/Si interface trap.

Key words: gate oxide process, TID, threshold voltage drift ΔVtn