Substrate processing method and substrate processing apparatus

Patent metadata

Field	Value
Publication number	US-10854469-B2
Application number	US-201815950557-A
Country	US
Kind code	B2
Filing date	Apr 11, 2018
Priority date	Apr 20, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

When a silicon concentration of a phosphoric acid aqueous solution inside a tank reaches an upper limit value of a specified concentration range, the phosphoric acid aqueous solution is drawn off from the tank and/or an amount of the phosphoric acid aqueous solution returning to the tank is decreased to decrease a liquid amount inside the tank to a value not more than a lower limit value of a specified liquid amount range. When the liquid amount inside the tank decreases to the value not more than the lower limit value of the specified liquid amount range, the phosphoric acid aqueous solution is replenished to the tank to increase the liquid amount inside the tank to a value within the specified liquid amount range and decrease the silicon concentration of the phosphoric acid aqueous solution inside the tank to a value within the specified concentration range.

First claim

What is claimed is:

1. A substrate processing method that supplies a phosphoric acid aqueous solution containing silicon to a substrate including a front surface at which a silicon oxide film and a silicon nitride film are exposed to selectively etch the silicon nitride film, the substrate processing method comprising:
a phosphoric acid storing step of storing the phosphoric acid aqueous solution, to be supplied to the substrate, in a phosphoric acid tank;
a phosphoric acid guiding step of guiding the phosphoric acid aqueous solution from the phosphoric acid tank to a phosphoric acid nozzle;
a phosphoric acid discharging step of making the phosphoric acid nozzle discharge the phosphoric acid aqueous solution toward the front surface of the substrate;
a substrate rotating step of rotating the substrate around a vertical rotation axis, passing through a central portion of the substrate, while holding the substrate horizontally in parallel to the phosphoric acid discharging process;
a phosphoric acid recovery step, starting at a time after the phosphoric acid aqueous solution was first supplied to the substrate from the phosphoric acid nozzle, of recovering to the phosphoric acid tank the phosphoric acid aqueous solution, that has been supplied to the substrate, by a phosphoric acid recovery unit, without also recovering to the phosphoric acid tank the phosphoric acid aqueous solution that was first supplied to the substrate;
a concentration detecting step of detecting a silicon concentration of the phosphoric acid aqueous solution inside the phosphoric acid tank;
a liquid amount decreasing step of, when the silicon concentration of the phosphoric acid aqueous solution inside the phosphoric acid tank reaches an upper limit value of a specified concentration range, decreasing a liquid amount of the phosphoric acid aqueous solution inside the phosphoric acid tank to a value not more than a lower limit value of a specified liquid amount range by decreasing an amount of the phosphoric acid aqueous solution returning to the phosphoric acid tank; and
a phosphoric acid replenishing step of, when the liquid amount of the phosphoric acid aqueous solution inside the phosphoric acid tank decreases to the value not more than the lower limit value of the specified liquid amount range in the liquid amount decreasing process, increasing the liquid amount of the phosphoric acid aqueous solution inside the phosphoric acid tank to a value within the specified liquid amount range and decreasing the silicon concentration of the phosphoric acid aqueous solution inside the phosphoric acid tank to a value within the specified concentration range by replenishing a phosphoric acid aqueous solution to the phosphoric acid tank from a phosphoric acid replenishing unit differing from the phosphoric acid recovery unit.

2. The substrate processing method according to claim 1 , wherein the phosphoric acid replenishing step includes a concentration changing step of changing the silicon concentration of the phosphoric acid aqueous solution to be replenished to the phosphoric acid tank from the phosphoric acid replenishing unit.

3. The substrate processing method according to claim 1 , wherein the phosphoric acid storing step includes a step of putting the phosphoric acid aqueous solution in contact with a liquid contacting portion, made of quartz, of the phosphoric acid tank.

4. The substrate processing method according to claim 1 , wherein
the substrate processing method further comprises a phosphoric acid heating step of heating, by a heater, the phosphoric acid aqueous solution before the phosphoric acid aqueous solution is supplied to the phosphoric acid nozzle, and
the phosphoric acid heating step includes a step of putting the phosphoric acid aqueous solution in contact with a liquid contacting portion, made of quartz, of the heater.

Assignees

• Screen Holdings Co Ltd

Inventors

• Hinode Taiki

Classifications

• H10P74/238

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H10P72/7618

  characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating carrousel · CPC title

• H10P72/0604

  Process monitoring, e.g. flow or thickness monitoring · CPC title

• H10P72/0424

  using mainly spraying means, e.g. nozzles · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title