TMAH is used in two main areas of semiconductor processing. In higher concentrations (25%) it is used as a crystallographic etch of silicon – similar to KOH etching. In lower concentrations (2.4%), it is used as a positive photoresist developer.
Higher All concentrations of TMAH solutions pose a severe toxic threat.
- TMAH acts to interfere with the nervous system, often shutting down breathing.
- There is no antidote at this time.
higher concentration greater than
- Death has occurred shortly (30 min) after exposure to quantities of
- as little as 7% body surface area exposed).
- Death occurred with 12% BSA of 8.75% TMAH
- So far, there have been no reported deaths due to exposure of developer strengths (one case had the patient on a respirator in intensive care - 28% BSA of 2.38% TMAH).
- The key to TMAH poisoning appears to be strength of solutions and area exposed. Time to decontamination does not appear to be important – absorption through skin may be very rapid.
- Symptoms of TMAH poisoning
- Muscle weakness
- 2nd or 3rd degree burns
- Irregular breathing and heartbeat
- Progressing to coma, shock and in most high concentration cases – death.