How small can MOSFETs go? 6.12J/3.155J Microelectronic processing 10 Four problems as size shrinks 1. Drai doping concentration Gate le ng th limited by thermodynamics 导 2. Physical tunnel through gate oxide (lot< lon) 01 3. Statistical fluctuations Junction depth of doping: Nd s 50/ (10 nm)3 ate 0.0 Oxide thic kness source 1970 1980 1990 2000 201[ Year Dec.10,2003D e c. 10 , 2 0 0 3 6.12J / 3.155J Microelectronic processing Four problems as size shrinks: 1. Drain, source doping concentration limited by thermodynamics 2. Physical tunneling through gate oxide (Ioff < Ion) 3. Statistical fluctuations of doping: Nd ≈ 50/(10 nm)3 4. Economic cost of Fab How small can MOSFETs go?