Table 6.
Results of alarms (n = 101) from gas detectors over 10 months from 2014 to 2015.
| Classification | N | % | |
|---|---|---|---|
| Type of gas † triggering alarm | TEOS [Si(OC2H5)4] | 44 | 43.6 |
| Difluoromethane [CH2F2] | 18 | 17.8 | |
| Hydrogen bromide [HBr] | 9 | 8.9 | |
| Hexafluorobutadiene [C4F6] | 5 | 5.0 | |
| TMB [B(CH3)3] | 5 | 5.0 | |
| Diborane [B2H6] | 3 | 3.0 | |
| Boron trichloride [BCl3] | 3 | 3.0 | |
| Others †† | 14 | 13.9 | |
| Cause of alarm events | Preventive maintenance work using isopropyl alcohol | 71 | 70.3 |
| Interruption | 7 | 6.9 | |
| Unknown | 17 | 16.8 | |
| Others ††† | 6 | 5.9 | |
| Level of alarm | >OEL and <2xOEL | 62 | 61.4 |
| ≥2xOEL | 39 | 38.6 |
† 47 (73.4%) of 64 gaseous chemicals used were monitored through 1486 gas detectors; †† Others: Cl2, CH4, HCl, AsH3, CF4, PH3, SiH4, SiHCl3, SiH2Cl2, TiCl4; ††† Others: alarm events occurred during the operation of alarm test, chamber open, parts replacement; TEOS: tetraethyl orthosilicate, TMB: trimethyl boron, OEL: occupational exposure limit.