There are strict restrictions on the usage in other equipments of wafers processed in KOH and NaOH. Those wafers MUST be decontaminated!
Decontamination procedure is the "extended SC2" (20 minutes) process as minimum. Always contact tool responsible if you have such plans. See e.g.
Work station dedicated for KOH etching of silicon. The concentration of KOH is 35-40 wt.% (in DI water). If the chemical level is too low (alarm will sound), fill up with DIW (carefully!) or contact tool responsible.The etching rate is approximately 65 µm/hour at 80 °C and it takes about 1 hour to heat up from R.T.
The KOH wetbench has dedicated, black-marked, wafer handling carriers. These should not be used anywhere else.
Always use full PPE, as KOH is a very strong corrosive chemical!
The bench ventilation should be ON at all times, so never turn it off! The bath circlulation only works during day-time 8 am to 7 pm. If you need overnight processing it can be arranged by contacting the tool responsible in advance.