Process Hierarchy

on front
  X-ray exposure
Field geometry
Shape of field with dimensions characterized by the maximum field size
Focal depth
Depth of focus of a single objective at a single setting (include objective)
400 .. 1000 µm
Material PMMA
Max field size 60 mm
Min feature size 5 µm
Sides processed either
Wafer size
Wafer size
Equipment X-ray beam line
Equipment characteristics:
Wafer geometry
Types of wafers this equipment can accept
no-flat, 1-flat, 2-flat, notched
Wafer holder
Device that holds the wafers during processing.
stainless steel
Wafer materials
List of wafer materials this tool can accept (not list of all materials, just the wafer itself).
glass (category), metal (category), Pyrex (Corning 7740), quartz (single crystal), silicon
Wafer thickness
List or range of wafer thicknesses the tool can accept
500 .. 1000 µm
  • Bottom dose for PMMA: 3.5 kJ/cc, ratio<4.
    Bottom dose for SU-8: 20-50 J/cc, ratio<2.5.
    Scan velocity: 5-50 mm/s.