Substrate cleaning method and substrate cleaning apparatus

Patent metadata

Field	Value
Publication number	US-9859110-B2
Application number	US-201715647900-A
Country	US
Kind code	B2
Filing date	Jul 12, 2017
Priority date	Sep 12, 2014
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

An ultrasonic wave applying liquid is supplied to one principal surface of a substrate while a liquid film of a first liquid being formed on another principal surface of the substrate. The ultrasonic wave applying liquid is obtained by applying ultrasonic waves to a second liquid. Ultrasonic vibration is transmitted to the other principal surface and the liquid film, thereby ultrasonically cleaning the other principal surface. The first liquid has a higher cavitation intensity, which is a stress per unit area acting on the substrate by cavitation caused in the liquid when ultrasonic waves are transmitted to the liquid present on the principal surface of the substrate, than the second liquid.

First claim

What is claimed is:

1. A substrate cleaning apparatus for cleaning a substrate that has one principal surface on which pattern elements are formed and another principal surface to be cleaned, the apparatus comprising:
a substrate holder for holding the substrate horizontally with the other principal surface faced vertically downward;
a first liquid discharger for discharging a first liquid to the other principle surface, wherein the first liquid discharger is fluidly connected to a first liquid source configured to provide the first liquid;
a liquid film former for forming a liquid film of the first liquid on the other principle surface;
a second liquid discharger for ultrasonically cleaning the other principle surface by discharging an ultrasonic wave applying liquid to the one principal surface while the liquid film of the first liquid is formed on the other principal surface and transmitting ultrasonic vibration from the one principal surface to the other principal surface and the liquid film of the first liquid formed on the other principal surface via the substrate, wherein the ultrasonic wave applying liquid is obtained by applying ultrasonic waves to a second liquid, and wherein the second liquid discharger is fluidly connected to a second liquid source configured to provide the second liquid; and
an ultrasonic wave applying first liquid discharger for discharging an ultrasonic wave applying first liquid toward the other principal surface, wherein the ultrasonic wave applying first liquid is obtained by applying ultrasonic waves to the first liquid;
wherein the first liquid has a higher cavitation intensity, which is a stress per unit area acting on the substrate by cavitation, than the second liquid discharged to the one principal surface.

2. The substrate cleaning apparatus according to claim 1 , wherein:
the second liquid discharger includes a nozzle for directly discharging the ultrasonic wave applying liquid to a partial area of the one principal surface; and
the nozzle relatively moves with respect to the substrate.

3. The substrate cleaning apparatus according to claim 2 , further comprising a substrate rotator for rotating the substrate held by the substrate holder about a center of rotation, wherein:
the second liquid discharger includes a moving mechanism for relatively moving the nozzle with respect to the substrate; and
the moving mechanism moves the nozzle in a radial direction from the center of rotation of the substrate toward a peripheral edge part of the substrate between a first position where the ultrasonic wave applying liquid is discharged toward the center of rotation of the substrate and a second position where the ultrasonic wave applying liquid is discharged toward the peripheral edge part of the substrate.

4. The substrate cleaning apparatus according to claim 2 , wherein:
the nozzle include a nozzle main body with a discharge port open toward the one principal surface and configured to discharge the ultrasonic wave applying liquid, an introducing portion for introducing a liquid into the nozzle main body and an oscillator for producing the ultrasonic wave applying liquid by applying ultrasonic waves to the liquid introduced into the nozzle main body; and
the oscillator has a concave surface facing the discharge port and converges ultrasonic waves included in the ultrasonic wave applying liquid outside the discharge port.

5. The substrate cleaning apparatus according to claim 4 , further comprising:
a position adjuster for adjusting the position of a convergence point where the ultrasonic waves included in the ultrasonic wave applying liquid converge; and
a direction adjuster for adjusting an angle of incidence of the ultrasonic wave applying liquid on the one principal surface.

6. The substrate cleaning apparatus according to claim 1 , wherein:
the second liquid source includes a degassing mechanism for degassing the second liquid, and the second liquid discharger produces the ultrasonic wave applying liquid by applying ultrasonic waves to the second liquid degassed by the degassing mechanism.

7. The substrate cleaning apparatus according to claim 1 , wherein:
the first liquid source includes a gas concentration adjusting mechanism for increasing a gas concentration in the first liquid by dissolving nitrogen gas, carbon dioxide, hydrogen gas, oxygen gas, ozone gas or air in the first liquid, and the first liquid discharger discharges the first liquid whose gas concentration is increased by the gas concentration adjusting mechanism to the other principle surface.

Assignees

• Screen Holdings Co Ltd

Inventors

• Hanawa Yosuke
• Miya Katsuhiko
• Sasaki Yuta

Classifications

• H10P72/0414

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

• H10P70/20 Primary

  Cleaning during device manufacture · CPC title

• G03F1/82

  Auxiliary processes, e.g. cleaning or inspecting · CPC title

• B08B3/12 Primary

  by sonic or ultrasonic vibrations · CPC title

• H01L21/02057 Primary

  Electricity · mapped topic