This paper has analyzed threshold voltage roll-off for bottom gate voltages of asymmetric double gate(DG) MOSFET. Since the asymmetric DGMOSFET is four terminal device to be able to separately bias for top and bottom gates, the bottom gate voltage influences on threshold voltage. It is , therefore, investigated how the threshold voltage roll-off known as short channel effects is reduced with bottom gate voltage. In the pursuit of this purpose, off-current model is presented in the subthreshold region, and the threshold voltage roll-off is observed for channel length and thickness with a parameter of bottom gate voltage as threshold voltage is defined by top gate voltage that off-currnt is ๎ด๎ฝ ๎บ ๎๎๎จ๎ฑ per channel width. As a result to observe the threshold voltage roll-off for bottom gate voltage using this model, we know the bottom gate voltage greatly influences on threshold voltage roll-off voltages, especially in the region of short channel length and thickness. ํค์๋ : ๋น๋์นญ ์ด์ค๊ฒ์ดํธ MOSFET, ๋ฌธํฑ์ ์์ด๋, ํ๋จ ๊ฒ์ดํธ ์ ์, ๋จ์ฑ๋ํจ๊ณผ Key word : asymmetric DGMOSFET, threshold voltage roll-off, bottom gate voltage, short channel effect Journal of the Korea Institute of Information and Communication Engineering ํ๋จ๊ฒ์ดํธ ์ ์์ ๋ฐ๋ฅธ ๋น๋์นญ ์ด์ค๊ฒ์ดํธ MOSFET์ ๋ฌธํฑ์ ์์ด๋ ์์กด์ฑ