Laser chamber, discharge-excitation-type gas laser device, and electronic device manufacturing method

A discharge-excitation type gas laser device comprising:

• an optical resonator;
• and
• a laser chamber arranged on an optical path of the optical resonator;
• the laser chamber including:
• first and second discharge electrodes arranged in the laser chamber as facing each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction;
• a fan arranged in the laser chamber, and configured to cause a laser gas in the laser chamber to circulate while rotating a flow direction of the laser gas about an axis parallel to the second direction;
• and
• a cooling unit arranged in the laser chamber, and configured to cool the laser gas,
• when the laser chamber is viewed in cross-section in a plane perpendicular to the second direction, at least a part of a gas guide surface out of an inner surface of the laser chamber extending between first and second virtual curves over a first section corresponding to a phase angle of a magnitude of 90° or more of first and second virtual logarithmic spirals,
• the part of the gas guide surface being a part from a first position on an upstream side in the flow direction of the laser gas to a second position on a downstream side therein,
• the inner surface defining a flow path of the laser gas through which the laser gas flows between the first and second discharge electrodes to a vicinity of the cooling unit,
• the first virtual curve having a curvature decreasing along the flow direction and being a virtual curve from a first phase angle to a second phase angle of the first virtual logarithmic spiral having an angle of 103° at which a straight line from a first origin and a tangent line of the first virtual curve intersect each other, and
• the second virtual curve having a curvature decreasing along the flow direction and being a virtual curve from the first phase angle to the second phase angle of the second virtual logarithmic spiral having an angle of 96° at which a straight line from the first origin and a tangent line of the second virtual curve intersect each other.

An electronic device manufacturing method, comprising:

• generating laser light using a discharge-excitation-type gas laser device;
• outputting the laser light to an exposure apparatus;
• and
• exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture an electronic device,
• the discharge-excitation-type gas laser device including:
• an optical resonator;
• and
• a laser chamber arranged on an optical path of the optical resonator;
• the laser chamber including:
• first and second discharge electrodes arranged in the laser chamber as facing each other in a direction parallel to a first direction, each of the first and second discharge electrodes extending in a second direction perpendicular to the first direction;
• a fan arranged in the laser chamber, and configured to cause a laser gas in the laser chamber to circulate while rotating a flow direction of the laser gas about an axis parallel to the second direction;
• and
• a cooling unit arranged in the laser chamber, and configured to cool the laser gas,
• when the laser chamber is viewed in cross-section in a plane perpendicular to the second direction, at least a part of a gas guide surface out of an inner surface of the laser chamber extending between first and second virtual curves over a first section corresponding to a phase angle of a magnitude of 90° or more of first and second virtual logarithmic spirals,
• the part of the gas guide surface being a part from a first position on an upstream side in the flow direction of the laser gas to a second position on a downstream side therein,
• the inner surface defining a flow path of the laser gas through which the laser gas flows between the first and second discharge electrodes to a vicinity of the cooling unit,
• the first virtual curve having a curvature decreasing along the flow direction and being a virtual curve from a first phase angle to a second phase angle of the first virtual logarithmic spiral having an angle of 103° at which a straight line from a first origin and a tangent line of the first virtual curve intersect each other, and
• the second virtual curve having a curvature decreasing along the flow direction and being a virtual curve from the first phase angle to the second phase angle of the second virtual logarithmic spiral having an angle of 96° at which a straight line from the first origin and a tangent line of the second virtual curve intersect each other.