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US-12623256-B2 - Substrate processing method and substrate processing apparatus

US12623256B2US 12623256 B2US12623256 B2US 12623256B2US-12623256-B2

Abstract

A substrate processing method according to the invention includes a supercritical process step of processing a substrate by a processing fluid in a supercritical state by introducing the processing fluid into an internal space of the chamber accommodating the substrate, a decompression step of decompressing the internal space by discharging the processing fluid, a carry-out step of carrying out the substrate from the chamber, and a temperature adjustment step of adjusting a temperature of the internal space to a target temperature by introducing and discharging the processing fluid to and from the internal space after the substrate is carried out. Stable processing efficiency can be obtained also particularly in the case of processing a plurality of substrates in turn by properly controlling a temperature in a chamber after a process in a technique for processing a substrate by a processing fluid in a supercritical state in the chamber.

Inventors

  • Noritake SUMI

Assignees

  • SCREEN Holdings Co., Ltd.

Dates

Publication Date
20260512
Application Date
20220316
Priority Date
20210323

Claims (6)

  1. 1 . A substrate processing method for processing a substrate by a processing fluid in a supercritical state in a chamber, the substrate processing method comprising: processing the substrate by the processing fluid in the supercritical state by introducing the processing fluid into an internal space of the chamber accommodating the substrate; decompressing the internal space by discharging the processing fluid; carrying out the substrate from the chamber; and adjusting a temperature of the internal space to a target temperature by introducing the processing fluid into the internal space and discharging the processing fluid from the internal space after the substrate is carried out, wherein the adjusting the temperature of the internal space involves cooling a wall surface of the chamber facing the internal space by adiabatic expansion of the processing fluid pressurized to a pressure higher than the atmospheric pressure in the internal space, and wherein a discharge rate in discharging the processing fluid from the internal space is set based on the target temperature.
  2. 2 . The substrate processing method according to claim 1 , wherein in the adjusting the temperature of the internal space, the processing fluid of which temperature is adjusted according to the target temperature is introduced into the internal space.
  3. 3 . The substrate processing method according to claim 2 , wherein the wall surface of the chamber facing the internal space is cooled by introducing the processing fluid having a temperature lower than the temperature of the internal space.
  4. 4 . The substrate processing method according to claim 1 , wherein a plurality of substrates are processed in turn by receiving a new unprocessed substrate and processing the unprocessed substrate with the processing fluid after the adjusting the temperature of the internal space.
  5. 5 . A substrate processing method for processing a substrate by a processing fluid in a supercritical state in a chamber, the substrate processing method comprising: processing the substrate by the processing fluid in the supercritical state by introducing the processing fluid into an internal space of the chamber accommodating the substrate; decompressing the internal space by discharging the processing fluid; carrying out the substrate from the chamber; and adjusting a temperature of the internal space to a target temperature by introducing the processing fluid into the internal space and discharging the processing fluid from the internal space after the substrate is carried out, wherein the adjusting the temperature of the internal space involves cooling a wall surface of the chamber facing the internal space by adiabatic expansion of the processing fluid pressurized to a pressure higher than the atmospheric pressure in the internal space, and wherein a discharge rate in discharging the processing fluid from the internal space is set based on the temperature of the internal space immediately before the processing fluid is introduced.
  6. 6 . A substrate processing method for processing a substrate by a processing fluid in a supercritical state in a chamber, the substrate processing method comprising: processing the substrate by the processing fluid in the supercritical state by introducing the processing fluid into an internal space of the chamber accommodating the substrate; decompressing the internal space by discharging the processing fluid; carrying out the substrate from the chamber; and adjusting a temperature of the internal space to a target temperature by introducing the processing fluid into the internal space and discharging the processing fluid from the internal space after the substrate is carried out, wherein the adjusting the temperature of the internal space involves cooling a wall surface of the chamber facing the internal space by adiabatic expansion of the processing fluid pressurized to a pressure higher than the atmospheric pressure in the internal space, and wherein: a plurality of supply/discharge recipes specifying changes of introduction and discharge of the processing fluid into and from the internal space are set in advance; and in the adjusting the temperature of the internal space, the introduction and discharge of the processing fluid into and from the internal space are controlled based on one supply/discharge recipe selected based on the temperature of the internal space immediately before the processing fluid is introduced.

Description

CROSS REFERENCE TO RELATED APPLICATION The disclosure of Japanese Patent Application No. 2021-048372 filed on Mar. 23, 2021 including specification, drawings and claims is incorporated herein by reference in its entirety. TECHNICAL FIELD This invention relates to a technique for processing a substrate by a processing fluid in a supercritical state in a chamber and particularly to a process after the substrate is processed with the supercritical processing fluid. BACKGROUND ART The process of processing various substrates such as a semiconductor substrate and a glass substrate for a display apparatus includes processing the surface of the substrate with various processing fluids. Although processing using liquids such as chemicals and rinses as the processing fluids has been widely performed in the past, processing using supercritical fluids has been put into practical use in recent years. In particular, in the processing of a substrate having a fine pattern formed on its surface, a supercritical fluid having a lower surface tension than a liquid penetrates deep into gaps among the pattern, whereby the processing may be performed efficiently. In addition, the risk of pattern collapse due to the surface tension may be reduced in a drying process. A substrate processing apparatus for drying a substrate by replacing a liquid adhering to the substrate by a supercritical fluid is described, for example, in PTL 1. More specifically, a flow of a drying process in the case of using carbon dioxide as a supercritical fluid and IPA (isopropyl alcohol) as a liquid to be replaced by carbon dioxide is described in detail in PTL 1. In this process, the inside of a chamber accommodating the substrate is filled with the processing fluid and a condition exceeding critical pressure and critical temperature of the processing fluid in the chamber is kept for a certain period. Thereafter, the inside of the chamber is decompressed and a series of processing ends. CITATION LIST Patent Literature PTL 1: JP 2018-081966A SUMMARY Technical Problem In the above conventional technique, the supercritical state is maintained mainly by a pressure control of repeating pressure increase and pressure reduction. However, the temperature and the pressure of the supercritical fluid during the processing are more preferably kept constant. The reason for that is that, since a density change particularly associated with a temperature change is very large in the supercritical fluid, processing efficiency is largely changed by a density of the processing fluid in a processing for the purpose of liquid replacement. More particularly, the higher density the supercritical processing fluid is, the more the other liquid can be taken. Thus, the replacement efficiency of the liquid increases. The lower the temperature, the higher the density of the supercritical processing fluid. Thus, the processing fluid preferably has as low and constant a temperature as possible within a range in which the supercritical state can be maintained. The temperature of the processing fluid is affected also by a chamber internal temperature when the processing fluid is introduced into the chamber. Thus, the temperature in the chamber at the time of introducing the processing fluid is also required to be constantly and properly kept. However, this point is not considered in the above conventional technique, and the chamber internal temperature is not managed at timings other than during the processing, particularly in a decompression process. Thus, particularly in the case of successively processing a plurality of substrates, the next substrate and the processing fluid may be possibly introduced into the chamber having reached a high temperature by the processing of the previous substrate. In this way, processing efficiency may be reduced or processing results may vary. Solution to Problem This invention was developed in view of the above problem and aims to provide a technique capable of obtaining stable processing efficiency also particularly in the case of processing a plurality of substrates in turn by properly controlling a temperature in a chamber after a process in a technique for processing a substrate by a processing fluid in a supercritical state in the chamber. One aspect of this invention is directed to a substrate processing method for processing a substrate by a processing fluid in a supercritical state in a chamber, the substrate processing method including a supercritical process step of processing the substrate by the processing fluid in the supercritical state by introducing the processing fluid into an internal space of the chamber accommodating the substrate, a decompression step of decompressing the internal space by discharging the processing fluid, a carry-out step of carrying out the substrate from the chamber, and a temperature adjustment step of adjusting a temperature of the internal space to a target temperature by introducing and discharging the proc