Object stage bearing for lithographic apparatus

An object stage bearing system comprising:

• an object stage configured to move along a hollow shaft;
• the hollow shaft including an interior channel configured to provide one or more supply lines into the object stage through an aperture of the hollow shaft;
• an in-vacuum gas bearing assembly directly connected to the hollow shaft and a first lateral side of the object stage, the in-vacuum gas bearing assembly comprising:
• a gas bearing disposed along an inner wall of the in-vacuum gas bearing assembly and disposed along an outer wall of the hollow shaft;
• a scavenging groove disposed along the inner wall such that the scavenging groove is isolated from the gas bearing using a first assembly wall of the in-vacuum gas bearing assembly disposed around the gas bearing and along the outer wall of the hollow shaft;
• and
• a vacuum groove disposed along the inner wall such that the vacuum groove is isolated from the scavenging groove and the gas bearing using a second assembly wall of the in-vacuum gas bearing assembly disposed around the gas bearing and the scavenging groove and along the outer wall of the hollow shaft, wherein the second assembly wall is formed as a separate wall from the first assembly wall;
• and
• a second in-vacuum gas bearing assembly opposite the in-vacuum gas bearing assembly along a longitudinal axis of the hollow shaft and directly connected to the hollow shaft and a second lateral side of the object stage,
• wherein the object stage is configured to house one or more supply lines for the gas bearing, and
• wherein the object stage is between the in-vacuum gas bearing assembly and the second in-vacuum gas bearing assembly.

An object stage bearing system comprising:

• a hollow shaft having a longitudinal axis, an interior channel, and an aperture;
• an object stage coupled to the hollow shaft and configured to move along the hollow shaft;
• one or more supply lines housed within the object stage, wherein the interior channel provides the one or more supply lines into the object stage through the aperture of the hollow shaft;
• and
• an in-vacuum gas bearing assembly coupled to and separate from the hollow shaft and the object stage, the in-vacuum gas bearing assembly comprising:
• a body;
• a gas bearing disposed along an inner wall of the body and disposed along an outer wall of the hollow shaft, wherein the gas bearing receives the one or more supply lines;
• a scavenging groove disposed along the inner wall and within the body such that the scavenging groove is isolated from the gas bearing using a first assembly wall of the body disposed around the gas bearing and along the outer wall of the hollow shaft;
• and
• a vacuum groove disposed along the inner wall and within the body such that the vacuum groove is isolated from the scavenging groove and the gas bearing using a second assembly wall of the body disposed around the gas bearing and the scavenging groove and along the outer wall of the hollow shaft, wherein the second assembly wall is separate from the first assembly wall,
• wherein the scavenging groove surrounds the gas bearing on both sides along the longitudinal axis of the hollow shaft.