C25 (similar to C23 and C21, but with larger sample window)

Images

Focus Ion Beam Milling

Date:   17.02.04 (DD.MM.YY)

Feature Radius target nm        [actual]  Mill current (pA)  Mill time (seconds) Magnification
Pinhole 1000 11 see p60 v3  
Broken Symmetry (square) none - -  
Terrace none - -  
Reference hole: top 150  [~300 x 400 nm] 11 17 50kX
bottom of reference hole penetrates very elliptical  119x195nm  
Center to center  4200 nm

Metal Films

Front side (membrane side) Pd(200)[Co(12)Pd(7)]_50 Pd(12) angstroms   Olav's code: e4196
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 magnetic multilayer and gold were deposited before the FIB was used.  Both the sample window and the reference hole were milled during the same session.  The sample window is 2 microns in diameter which is larger than normal.  A stubborn grain was present when the sample window was milled, this required a great deal of targeted milling on the grain which is detailed on p60 v3.  In the end the window has some gold left in the window, but the membrane was not penetrated so the magnetic multilayer was undisturbed.