Process Hierarchy

  Aluminum wet etch
Process characteristics:
Depth of material removed by etch process
Depth of material removed by etch process, must be 0 .. 2 µm
0 .. 2 µm
Batch size 25
Etch rate 0.25 µm/min
Solutions and their concentrations.
Ashland's 16:1:1:2 Aluminum Etch
Mask materials
Materials that can be used to mask etching.
photoresist (category)
Material aluminum
Min feature size 1 µm
Primary material removal rate divided by removal rates of secondary materials (i.e., factors by which primary material is removed faster than secondary materials)
aluminum: 1
Sides processed both
Temperature 40 °C
Undercut rate
Length of undercut as a function of time
0.004 µm/s
Wafer size
Wafer size
Equipment Metal wet bench
Equipment characteristics:
Wafer geometry
Types of wafers this equipment can accept
no-flat, 1-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, glass (category), quartz (single crystal), sapphire, silicon on insulator, silicon on sapphire
Wafer thickness
List or range of wafer thicknesses the tool can accept
300 .. 700 µm
  • MOS clean process.