Water with surfactant:

To remove large particulates not strongly bonded to the surface, a surfactant (like soap or Tergitol) in DI water with ultrasonic agitation is effective at removing this type of dirt. Follow with running DI rinse.


Solvent with Ultrasound:

For some larger particles/organic residues, ultrasonic agitation in a solvent such as Acetone can work.


Wet Etchants:

Some particulates can be effectively oxidized and removed by strong oxidizers.

  1. RCA Clean (preferred process) (step 1 is enough for most of our work):
    a) NH4OH:H2O2:DI 1:1:5 at 80°C for > 5 minutes. Finish with a DI rinse.
    b) HCl:H2O2:DI  1:1:6 at 80°C for 5 minutes. DI rinse.
    Note: a) will etch GaAs
  2. Pirhana etch:
    a) H2SO4:H2O2 4:1 90°C for 10 minutes.
    b) DI rinse and dry.
    Note: a) will etch both GaAs and InP related compounds


Reference: See Chapter 2 of “ULSI Technology” by C.Y. Chang and S.M. Sze for further information.


Technical and educational staff services are possible through the generosity of the National Science Foundation through support via the NNIN.