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