Process Hierarchy

If you are interested in this process, either by itself or as part of a longer processing sequence, please send us email at engineering@mems-exchange.org or call us at (703) 262-5368
  Polysilicon wet etch
Process characteristics:
Depth
Depth of material removed by etch process
Depth*
Depth of material removed by etch process, must be 0 .. 4 µm
0 .. 4 µm
Batch size 12
Etch rate 3100 Å/min
Etchant
Solutions and their concentrations.
 HNO3/H2O/HF [50:20:1]
Material polysilicon
Selectivity
Primary material removal rate divided by removal rates of secondary materials (i.e., factors by which primary material is removed faster than secondary materials)
 photoresist (category): 200, polysilicon: 1, silicon nitride: 1500
Sides processed both
Temperature 25 °C
Wafer size
Wafer size
Equipment Sink 7
Equipment characteristics:
Wafer geometry
Types of wafers this equipment can accept
 1-flat, no-flat
Wafer holder
Device that holds the wafers during processing.
 teflon cassette
Wafer materials
List of wafer materials this tool can accept (not list of all materials, just the wafer itself).
 silicon
Wafer thickness
List or range of wafer thicknesses the tool can accept
 300 .. 600 µm
Comments:
  • Recommended masking materials are photoresist and silicon nitride.