How much evaporant strikes substrate? At 10-6 Torr, trajectories are uninterrupted While a point source deposits uniformly on a sphere about it, a planar source does not J∝ccos, substrate ubstrate R R Convenient geometry R Geometric factor cos 6, cos 6. cos0,=cos0 2R 2r Geometric factor eposition rate 4丌-area·borJ 4mr2\area·t A 1 thick Film growth rate =Jm 4m2(t 6.152J3.155J6.152J/3.155J 10 How much evaporant strikes substrate? At 10-6 Torr, trajectories are uninterrupted. While a point source deposits uniformly on a sphere about it, a planar source does not: Geometric factor = Ac 2πR2 cosθ1 cosθ 2 cosθ1 = cosθ 2 = R2r Deposition rate = Jm Ac 4πr 2 m area⋅ t      or J Ac 4πr2 # area ⋅ t     substrate θ1 θ2 R R θ1 θ2 r r substrate Convenient geometry Geometric factor = Ac 4πr2 Film growth rate = Jm Ac 4πr 2 1 ρ f thick t      ∝cosθ1 J