Exercise Deposit Al (2.7 g/cm )at r=40 cm from 5 cm diam crucible heated to 1100 C (cf T melt PAl vap 10- Torr, PHo=10 Torr ( this is not good) Compare arrival rate of Al and H,O at substrate.. and calculate film growth 0/760)×10 0√2zx(03×)×(N) 48×108 molecules IS m 03×10/760) Npx×(373)×27/N)4m2 =1.76×108 atoms m s P sure≈10-m/ s slow Pm 40212rk B source Leave shutter closed so initial Al deposition can getter O, and h,o Also, better done at lower PH o or higher deposition rate 6.152J3.155J6.152J/3.155J 12 Exercise Deposit Al (2.7 g/cm3) at r = 40 cm from 5 cm diam. crucible heated to 1100°C (cf Tmelt) pAl vap ≈ 10-3 Torr, pH2O =10−6Torr Compare arrival rate of Al and H2O at substrate…and calculate film growth rate JH2O = 10−6 ( ) 760 ×105 2π ×( ) 0.025eV × e × ( ) 18 NA = 4.8 ×1018 molecules m 2 s JAl = 10−3 ×105 ( ) 760 2π × 1373k ( )B ×( ) 27 NA Ac 4πr2       =1.76 ×1018 atoms m2s Ac = π 52    2 Leave shutter closed so initial Al deposition can getter O2 and H2O. Also, better done at lower or p higher deposition rate. H2O (this is not good) v = pvap ρ m Ac 4πr2 msource 2πkBTsource ≈10−11 m /s slow!