CPC H01L 21/32134 (2013.01) [H01L 21/02052 (2013.01); H01L 21/32055 (2013.01); H01L 21/67023 (2013.01); H01L 21/68764 (2013.01)] | 10 Claims |
1. A substrate processing method to supply an alkaline etching liquid to a substrate on which an etching object including polysilicon and a non-etching object different from the etching object are exposed, the substrate processing method comprising:
an etching liquid making step of making the alkaline etching liquid including quaternary ammonium hydroxide, water and inhibitor that inhibits contact of a hydroxide ion generated from the quaternary ammonium hydroxide and the etching object; and
a selective etching step of etching the etching object while inhibiting etching of the non-etching object by supplying the etching liquid made in the etching liquid making step to the substrate on which the etching object and the non-etching object are exposed, wherein
the etching liquid making step includes a concentration determining step of determining concentration of the inhibitor in the etching liquid based on a target value of a difference of etching speeds of a plurality of crystal planes of a silicon single crystal constituting the polysilicon.
|