Skip to main content

Silicon Wafer Preparation Workstation

This page provides details on the wet-chemistry processing workstation for preparing silicon wafers in the Stand-Alone Measurements and Characterization bays of the Process Development and Integration Laboratory (PDIL). This capability should be operational by late 2009.

Silicon wafer surfaces must be prepared and cleaned carefully and reliably for many deposition and characterization techniques, such as minority-carrier lifetime measurements, defect etching, and texture etching. With this wet-processing stand-alone tool, any sample surface can be quickly passivated, etched, or cleaned before being transported to another tool. Samples can be amorphous and crystalline silicon, and can also include cadmium telluride or other roadmap materials if liners or other precautions are taken to prevent contamination of tanks.

Photo of white cabinet on legs, with a window on the front of the upper half.  A keyboard and monitor are located to the right. The cabinet has a label that says "Corrosive."

Wet bench unit that is one of the Stand-alone Measurements and Characterization tools in the Process Development and Integration Laboratory.


  • Preparing silicon wafers and passivating surfaces for lifetime measurements
  • Removing oxides
  • Doing H-termination
  • Defect etching

Special features:

  • Laminar chemical hood
  • Robotic wafer handler
  • Cassette for six 157-mm x 157-mm silicon wafers
    • Piranha (H2SO4 + H202) static, heated quartz bath with temperature control at 80°C
    • Automatic H2O2 injection
  • Defect etching tank
    • Nitric, acetic, and hydrofluoric (HF) acids
    • N2 bubbler for agitation
    • At room temperature
  • Buffered HF tank
    • HF and ammonium fluoride
    • N2 bubbler for agitation
    • At room temperature
  • Quick-dump rinse
  • Teflon guns for N2 and deionized water

Contact Bhushan Sopori for more details.