Substrate processing method and substrate processing device

Abstract

A substrate processing method includes a substrate holding step of holding a substrate having a front surface on which a metal is exposed, an inert gas replacing step of replacing an atmosphere around the front surface of the substrate with an inert gas by supplying an inert gas to a vicinity of the front surface of the substrate, an adjusting step of adjusting a pH of the rinsing liquid so as to form an inactive state in which the metal does not react with the rinsing liquid or so as to form a passive state by allowing the metal to react with the rinsing liquid, and a rinsing liquid supplying step of supplying the rinsing liquid whose pH has been adjusted to the front surface of the substrate after the atmosphere around the front surface of the substrate has been replaced with the inert gas.

1 . A substrate processing method comprising:
 a substrate holding step of holding a substrate having a front surface on which a metal is exposed;   an inert gas replacing step of replacing an atmosphere around the front surface of the substrate with an inert gas by supplying an inert gas to a vicinity of the front surface of the substrate;   an adjusting step of adjusting a pH of a rinsing liquid so as to form an inactive state in which the metal does not react with the rinsing liquid or so as to form a passive state by allowing the metal to react with the rinsing liquid;   a rinsing liquid supplying step of supplying the rinsing liquid whose pH has been adjusted to the front surface of the substrate after the atmosphere around the front surface of the substrate has been replaced with the inert gas;   a chemical liquid supplying step of, before the rinsing liquid supplying step, supplying a chemical liquid that is capable of forming salt with the rinsing liquid to the front surface of the substrate;   a pre-rinsing liquid supplying step of, after the chemical liquid supplying step and before the rinsing liquid supplying step, washing away a chemical liquid adhering to the front surface of the substrate by supplying ultrapure water to the front surface of the substrate; and   an electric charge reducing step of causing a flow rate of the ultrapure water in the pre-rinsing step to be in a range of 0.5 L/min or less, thereby to reduce an electric charge amount on the front surface of the substrate.   
     
     
         2 . The substrate processing method according to  claim 1 , wherein the adjusting step includes a step of adjusting the pH of the rinsing liquid by mixing the rinsing liquid and a pH adjustment fluid together. 
     
     
         3 . The substrate processing method according to  claim 1 , further comprising: an organic solvent replacing step of replacing the rinsing liquid on the front surface of the substrate with an organic solvent that is miscible with the rinsing liquid by supplying the organic solvent to the front surface of the substrate. 
     
     
         4 . The substrate processing method according to  claim 1 , further comprising: a substrate rotating step of rotating the substrate around a rotational axis along a vertical direction in the pre-rinsing liquid supplying step,
 wherein the electric charge reducing step causes a rotational speed of the substrate in the substrate rotating step to be in a range of 500 rpm or less.   
     
     
         5 . The substrate processing method according to  claim 1 , wherein, in the adjusting step, the pH of the rinsing liquid and an oxidation-reduction potential of the rinsing liquid are adjusted so as to form an inactive state in which the metal does not react with the rinsing liquid or so as to form a passive state by allowing the metal to react with the rinsing liquid, and
 in the rinsing liquid supplying step, the rinsing liquid whose pH and whose oxidation-reduction potential have been adjusted is supplied to the front surface of the substrate.   
     
     
         6 . The substrate processing method according to  claim 5 , wherein the adjusting step includes a step of adjusting the oxidation-reduction potential of the rinsing liquid by mixing the rinsing liquid and an oxidation-reduction potential adjustment fluid together. 
     
     
         7 . The substrate processing method according to  claim 6 , wherein the oxidation-reduction potential adjustment fluid includes at least one kind among hypochlorous acid, periodic acid, chlorous acid, nitric acid, ammonium persulfate, hydrogen peroxide water, ammonia water, ammonia gas, and hydrogen. 
     
     
         8 . The substrate processing method according to  claim 5 , wherein, in the adjusting step, the oxidation-reduction potential of the rinsing liquid that is used in the rinsing liquid supplying step is adjusted to be in a range of −0.5 V or more and 1.0 V or less. 
     
     
         9 . The substrate processing method according to  claim 1 , wherein, in the adjusting step, the pH of the rinsing liquid that is used in the rinsing liquid supplying step is adjusted to be in a range of 7 or more and 10 or less. 
     
     
         10 . The substrate processing method according to  claim 1 , further comprising: a degassing step of degassing the rinsing liquid prior to the adjusting step. 
     
     
         11 . The substrate processing method according to  claim 1 , wherein the substrate is horizontally held in the substrate holding step,
 an inert gas is supplied to a vicinity of the upper surface of the substrate in the inert gas replacing step, and   the method further comprises a proximity step of moving a facing member that faces the substrate from above such that a facing surface of the facing member is placed at a proximal position close to the upper surface of the substrate between the inert gas replacing step and the rinsing liquid supplying step.   
     
     
         12 . The substrate processing method according to  claim 1 , wherein, in the inert gas replacing step, an inert gas is supplied such that an oxygen concentration in the atmosphere around the front surface of the substrate becomes 250 ppm or less.