APPARATUS AND METHOD FOR PROCESSING SUBSTRATE USING SUPERCRITICAL FLUID

A substrate processing method using a supercritical fluid is provided that can deposit a conformal film in a trench with a high aspect ratio and allows complete filling without voids. The substrate processing method comprises performing a supercritical process by repeating a first step, a first vent step, a second step, and a second vent step a plurality of times in order, supplying, in the first step, a first process fluid containing a precursor and a first supercritical fluid to a reactor so that a pressure of the reactor repeats rise and fall within a first pressure range a plurality of times, venting, in the first vent step, the reactor to lower the pressure of the reactor below the first pressure range, supplying, in the second step, a second process fluid containing a reducing fluid to the reactor so that the pressure of the reactor repeats rise and fall within a second pressure range different from the first pressure range a plurality of times, venting, in the second vent step, the reactor to lower the pressure of the reactor below the second pressure range.