APPARATUS AND METHOD FOR TREATING SUBSTRATES

An apparatus and a method for processing a substrate are provided to minimize the gelling of poly-silazane based chemicals in a pipe by forming nitrogen gas atmosphere in an exhaust pipe to block reaction of the poly-silazane based chemicals with moisture and oxygen. A substrate(W) is placed on a rotatable substrate supporting member(100). A chemical supplying member(200) supplies chemicals to the substrate. A bowl(300) is arranged to surround the substrate supplying member. The bowl includes a chemical exhaust hole(312) and an air exhaust hole(314) to separate the chemical dispersed by rotation of the substrate from air and to exhaust the separated chemical and the air. A chemical exhaust unit(400) is connected to the chemical exhaust hole of the bowl. The dispersed chemicals flowed in the bowl are exhausted and stored in the chemical exhaust unit. A purge gas supplying member(500) supplies purge gas to the chemical exhaust unit.