US 7,030,959 B2 · Extreme ultraviolet reticle protection using gas flow thermophoresis

Abstract

Methods and apparatus for using a flow of a relatively cool gas to establish a temperature gradient between a reticle and a reticle shield to reduce particle contamination on the reticle are disclosed. According to one aspect of the present invention, an apparatus that reduces particle contamination on a surface of an object includes a plate and a gas supply. The plate is positioned in proximity to the object such that the plate, which has a second temperature, and the object, which has a first temperature, are substantially separated by a space. The gas supply supplies a gas flow into the space. The gas has a third temperature that is lower than both the first temperature and the second temperature. The gas cooperates with the plate and the object to create a temperature gradient and, hence, a thermophoretic force that conveys particles in the space away from the object.

Claims38

Dependent claims

An apparatus arranged to reduce particle contamination on a surface of an object, the apparatus comprising:

a member having a surface proximate to the object, the member being arranged in proximity to the object such that the member and the object are substantially separated by a space, wherein the object is of a first temperature and the member is of a second temperature;
and
a gas supply, the gas supply being arranged to supply a gas flow to the space, the gas having in the space a temperature distribution the minimum of which is lower than the first temperature and lower than the second temperature, wherein the gas is arranged to cooperate with the member and the object to create a thermophoretic force to convey any particles in the space away from the object.

An apparatus arranged to reduce particle contamination on a surface of an object, the apparatus comprising:

a chamber, the chamber having a first region and a second region, the first region having a pressure of at least approximately 50 mTorr, the second region having a pressure that is less than the pressure of the first region;
a first scanning arrangement, the first scanning arrangement being arranged to scan the object, the first scanning arrangement being arranged in the first region, wherein the first scanning arrangement includes a member, the member being arranged in proximity to a first surface of the object such that a first surface of the member and the first surface of the object are substantially separated by a space in the first region, wherein the first surface of the object is of a first temperature and the first surface of the member is of a second temperature;
and
a gas supply, the gas supply being arranged to supply a gas flow to the space, the gas having in the space a temperature distribution the minimum of which is lower than the first temperature and lower than the second temperature, wherein the gas is arranged to cooperate with the member and the object to create a thermophoretic force to convey any particles in the space away from the object.

1 more element

Dependencies are inferred from the claim text.

Extreme ultraviolet reticle protection using gas flow thermophoresis

Life of this patent

Extreme ultraviolet reticle protection using gas flow thermophoresis

Life of this patent

Abstract

Claims38