Quartz glass shield for fab lamp
On the lithography line, a lamp drifting just 0.5°C during photoresist bake can quietly push linewidths out of spec, and those wafers end up flagged...
Quartz boat heating lamp fab
On the 24/7 fab floor, you don’t get to pretend a drift of half a degree doesn’t matter. A soft bake or hard bake that’s off by 0.5°C can move CD,...