C24 (similar to C18, only better)

Images

Focus Ion Beam Milling

Date:   6.02.04

Feature Radius target nm        [actual]  Mill current (pA)  Mill time (seconds) Magnification
Pinhole 500 10 45  
Broken Symmetry (square) 500 1 120  
Terrace 250 1 100   
Reference hole: top 20   [r=100nm] 1 15 150 kX
Reference hole: bottom penetrates completely                diameter 70nm x 60nm      
Center to center  2000 nm

Metal Films

Front side (membrane side) non
Back side (pit side) Cr 2nm/ Au 600nm

Membrane Specifications

Size (micrometers)  200 x 200
Thickness (nm) 100
Frame size (mm) 5x5
Frame thickness (micrometers) 200
   

Comments: The reference hole for this mask is small and penetrates completely.  It is better than C18 which had an obstructed reference hole that was slightly larger.