JP2005191166A5

JP2005191166A5 -

Info

Publication number: JP2005191166A5
Application number: JP2003428758A
Authority: JP
Filing date: 2003-12-25
Publication date: 2006-04-27

Claims

A light source;
Optical system,
A reticle stage that can hold the reticle;
A gas supply means capable of maintaining the periphery of the reticle in an atmosphere containing an active gas having a concentration of 5 to 500 ppm ;
A transmittance measuring means capable of measuring a change in transmittance of the reticle;
A wafer stage on which a wafer can be placed;
With
Light cleaning that removes contaminants attached to the reticle by irradiating light onto the reticle from the light source while maintaining the atmosphere around the reticle by the gas supply means in an atmosphere containing the active gas is enabled. A projection exposure apparatus.

An illuminance sensor for measuring the illuminance of light irradiated on the wafer;
A control mechanism for determining an exposure time for the wafer from the illuminance measured by the illuminance sensor;
The projection exposure apparatus according to claim 1, further comprising: determining the exposure time after the light cleaning.

A concentration measuring mechanism for measuring the concentration of the active gas in the atmosphere around the reticle;
A concentration control mechanism for controlling the concentration of the active gas according to the output of the concentration measurement mechanism;
The projection exposure apparatus according to claim 1, further comprising:

The active gas is at least one selected from the group consisting of O ₂ , O ₃ , CO ₂ , CO, nitric oxides (NO _X ), sulfur oxides (SO _X ), and oxygen. The projection exposure apparatus according to any one of claims 1 to 3.

The atmosphere containing the active gas includes the active gas and an inert gas,
The projection exposure apparatus according to claim 1, wherein the inert gas is one selected from the group consisting of N ₂ , Ar, and He.

6. The projection exposure apparatus according to claim 1, wherein the optical cleaning is stopped when a change in the transmittance measured by the transmittance measuring unit falls below a predetermined value.

The projection exposure apparatus according to claim 1, wherein the transmittance measuring unit measures the transmittance at a portion of a transmittance measuring window provided on the reticle.

The projection exposure apparatus according to claim 1, wherein the light source emits F2 laser light.

Light cleaning that removes contaminants attached to the reticle by irradiating the reticle with light while maintaining the atmosphere around the reticle in an atmosphere containing an active gas causes the change in the transmittance of the reticle to fall below a predetermined value. A first step to be carried out until
A second step of performing exposure by irradiating the wafer with light through the reticle;
A projection exposure method comprising:

The projection exposure method according to claim 9, wherein the concentration of the active gas in the atmosphere containing the active gas is 5 ppm or more and 500 ppm or less.

Purging with an inert gas is performed to remove the active gas contained in the atmosphere around the reticle after the light cleaning and before the exposure of the wafer. The projection exposure method according to claim 9 or 10.