Process Hierarchy

  HF release etch
Process characteristics:
Depth of material removed by etch process
Depth of material removed by etch process, must be 0 .. 10 µm
0 .. 10 µm
Batch size 6
Etch rate 2.3 µm/min
Solutions and their concentrations.
HF [49%]
Material silicon dioxide
Primary material removal rate divided by removal rates of secondary materials (i.e., factors by which primary material is removed faster than secondary materials)
phosphosilicate glass: 0.6, silicon dioxide: 1
Sides processed both
Temperature 23 °C
Wafer size
Wafer size
Equipment Wetbench
  • bkla
Equipment characteristics:
Piece dimension
Range of wafer piece dimensions the equipment can accept
0 .. 4 inch
Piece geometry
Geometry of wafer pieces the equipment can accept
triangular shard, other, rectangular, irregular, circular
Piece thickness
Range of wafer piece thickness the equipment can accept
100 .. 1000 µm
Wafer geometry
Types of wafers this equipment can accept
1-flat, 2-flat, notched, no-flat
Wafer holder
Device that holds the wafers during processing.
teflon carrier
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
100 .. 1000 µm
  • Used to etch sacrificial
    layers of silicon dioxide and PSG.