Substrate processing method and substrate processing apparatus
According to the present invention, a substrate W is provided with a recess 95 . The width of the recess 95 is smaller than the depth of the recess 95 . An etching target which is at least one of a single crystal of silicon, a polysilicon and an amorphous silicon is exposed in at least a part of the upper part of a lateral surface 95 s and in at least a part of the lower part of the lateral surface 95 s . The etching target is etched by supplying an alkaline first etching liquid, in which an inert gas is dissolved, to the substrate W. The etching target is etched by supplying an alkaline second etching liquid, in which a dissolution gas is dissolved, and which has a dissolved oxygen concentration higher than that of the first etching liquid, to the substrate W before or after the first etching liquid is supplied to the substrate W.
1 . A substrate processing method comprising:
etching an etching target exposed on a side surface of a recess by supplying alkaline first etching liquid in which inert gas is dissolved to a substrate on which the recess is formed, the recess having a width shorter than a depth of the recess, the recess including the etching target that represents at least one of silicon single crystal, polysilicon and amorphous silicon and that is exposed on at least a portion of an upper portion of the side surface of the recess and at least a portion of a lower portion of the side surface; and
etching the etching target exposed on the side surface of the recess by supplying the substrate with alkaline second etching liquid in which dissolution gas is dissolved and having dissolved oxygen concentration higher than that of the first etching liquid wherein
the width of the recess before the first etching liquid and the second etching liquid are supplied decreases as a bottom of the recess is approached, and
in etching the etching target exposed on the side surface of the recess by supplying the substrate with the second etching liquid, an etching amount of the side surface of the recess increases as the bottom of the recess is approached.
2 . The substrate processing method according to claim 1 , wherein etching the etching target exposed on the side surface of the recess by supplying the substrate with the second etching liquid is etching the etching target exposed on the side surface of the recess by supplying the substrate with the second etching liquid after etching the etching target exposed on the side surface of the recess by supplying the first etching liquid to the substrate.
3 . The substrate processing method according to claim 2 , wherein in etching the etching target exposed on the side surface of the recess by supplying the substrate with the second etching liquid, the first etching liquid that is in contact with the substrate is replaced with the second etching liquid by supplying the second etching liquid to the substrate.
4 . The substrate processing method according to claim 1 , wherein
in etching by supplying the substrate with the first etching liquid, the first etching liquid is made by diluting alkaline undiluted liquid of the etching liquid with at least one of first diluting liquid and second diluting liquid having different dissolved oxygen concentrations, and
in etching by supplying the substrate with the second etching liquid, the second etching liquid is made by diluting the undiluted liquid with at least one of the first diluting liquid and the second diluting liquid.
5 . The substrate processing method according to claim 1 , wherein the substrate processing method processes a plurality of substrates one by one.
6 . The substrate processing method according to claim 1 , wherein the substrate processing method processes a plurality of substrates in a batch.