Process Hierarchy

  Polysilicon wet etch
Process characteristics:
Depth of material removed by etch process
Depth of material removed by etch process, must be 0 .. 4 µm
0 .. 4 µm
Batch size 12
Etch rate 3100 Å/min
Solutions and their concentrations.
HNO3/H2O/HF [50:20:1]
Material polysilicon
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).
Wafer thickness
List or range of wafer thicknesses the tool can accept
300 .. 600 µm
  • Recommended masking materials are photoresist and silicon nitride.