Method and apparatus for hydrophobic treatment

An apparatus for treating a surface of a substrate to make said surface hydrophobic comprising:

• a process chamber;
• support means for supporting a substrate, arranged within said process chamber;
• temperature adjusting means for adjusting treatment temperature of said substrate;
• a gas supply pipe communicating with said process chamber for supplying a mixed gas consisting of a vaporized treating agent and a carrier gas into said process chamber;
• a discharge pipe communicating with said process chamber for discharging a waste gas from said process chamber;
• concentration measuring means connected to said discharge pipe for measuring a concentration of said treating agent within said waste gas flowing within said discharge pipe;
• and
• control means for comparing the concentration value measured by said concentration measuring means with a reference value, which is determined on a basis of degree of progress of the hydrophobic treatment, so as to change at least one of treatment conditions of said substrate based on the result of comparison,
• wherein said concentration measuring means comprises a synthetic bimolecular film sensor including an oscillator and a synthetic bimolecular film covering said oscillator, the oscillation frequency of said oscillator being changed depending on the amount of said treating agent absorbed on said synthetic bimolecular film so as to measure the concentration of said treating agent within said waste gas,
• wherein said concentration measuring means comprises a container housing said sensor and connected to said discharge pipe, and
• wherein a purging pipe is connected to said container for purging said container with a gas having a composition substantially the same as that of said carrier gas.