Substrate processing apparatus, substrate processing method and substrate processing liquid
In one embodiment, a substrate processing liquid contains phosphoric acid as a primary component and contains water and ketone. In another embodiment, a substrate processing method includes processing a substrate in a substrate processing bath with a substrate processing liquid containing phosphoric acid, water and ketone. The method further includes discharging the substrate processing liquid from the substrate processing bath to a circulating flow channel, heating the substrate processing liquid flowing through the circulating flow channel at a temperature between 50° C. and 90° C., and supplying the substrate processing liquid again from the circulating flow channel to the substrate processing bath to circulate the substrate processing liquid under heating.
1. A substrate processing method comprising:
processing a substrate in a substrate processing bath by wet etching with a substrate processing liquid comprising phosphoric acid, water, ketone, and an oxidizing agent. wherein the ketone is liquid at 20° C., has vapor pressure of 30 mmHg or less at 20° C., and has viscosity of 1.0 cP or less at 20° C.;
discharging the substrate processing liquid from the substrate processing bath to a circulating flow channel, heating the substrate processing liquid flowing through the circulating flow channel at a temperature between 50° C. and 90° C., and supplying the substrate processing liquid again from the circulating flow channel to the substrate processing bath to circulate the substrate processing liquid under heating; and
purifying the heated substrate processing liquid with a filter in a purifying module provided on the circulating flow channel, wherein
a concentration of the phosphoric acid in the substrate processing liquid is 50 to 95 wt %,
a concentration of the water in the substrate processing liquid is 4 to 49.5 wt %,
a concentration of the ketone in the substrate processing liquid is 0.5 to 15 wt %, and
a concentration of the oxidizing agent in the substrate processing liquid is 0.1 to 10 wt %.
2. The method of claim 1 , wherein the ketone is selected from diethyl ketone, methyl propyl ketone, and dipropyl ketone.
3. The method of claim 1 , wherein the oxidizing agent comprises at least one of hydrogen peroxide having a concentration of 0.1 to 10 wt % in the substrate processing liquid and ozone having a concentration of 0.1 to 10 wt % in the substrate processing liquid.
4. A substrate processing apparatus comprising:
a substrate processing bath configured to process a substrate by wet etching with a substrate processing liquid comprising phosphoric acid, water, ketone, and an oxidizing agent, wherein the ketone is liquid at 20° C., has vapor pressure of 30 mmHg or less at 20° C., and has viscosity of 1.0 cP or less at 20° C.;
a circulating flow channel configured to circulate the substrate processing liquid by supplying the substrate processing liquid discharged from the substrate processing bath again to the substrate processing bath;
a heater configured to heat the substrate processing liquid flowing through the circulating flow channel; and
a purifying module configured to purify, with a. filter, the substrate processing liquid that flows through the circulating flow channel and is heated by the heater, wherein
a concentration of the phosphoric acid in the substrate processing liquid is 50 to 95 wt %,
a concentration of the water in the substrate processing liquid is 4 to 49 5 wt %,
a concentration of the ketone in the substrate processing liquid is 0.5 to 15 wt %, and
a concentration of the oxidizing agent in the substrate processing liquid is 0.1 to 10 wt %.
5. The apparatus of claim 4 , wherein the oxidizing agent comprises at least one of hydrogen peroxide having a concentration of 0.1 to 10 wt % in the substrate processing liquid and ozone having a concentration of 0.1 to 10 wt % in the substrate processing liquid.
6. The apparatus of claim 4 , wherein the substrate processing liquid is contained in the substrate processing bath.
7. The apparatus of claim 6 , wherein the oxidizing agent comprises at least one of hydrogen peroxide having a concentration of 0.1 to 10 wt % in the substrate processing liquid and ozone having a concentration of 0.1 to 10 wt % in the substrate processing liquid.