Stage apparatus and exposure apparatus

• US 20080036989A1
• Filed: 07/12/2007
• Published: 02/14/2008
• Est. Priority Date: 07/14/2006
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Shibazaki, Yuichi
• Application Number:
  US11/826,144
• Publication Number:
  US 20080036989A1
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: H01L 21/682 Mask-wafer alignment in general G03F7/70, G03F9/70

Abstract

A wafer stage system moves a wafer stage that retains a wafer via a wafer holder along a wafer base. For example, the wafer holder is formed from a material whose density is not uniform, such that the portion that includes the reflecting surface that reflects a measuring beam for position measurement is a high-density portion, and the other portions are low-density portions. Or, the wafer stage is formed from a material whose density is not uniform, such that the portion that includes the surface that constitutes a gas bearing is a high-density portion, and the other portions are low-density portions.

Claims

1. A stage apparatus comprising:

a moving portion on which an object is placed;

a guide portion that guides the moving portion; and

a predetermined member that is provided on at least one of the moving portion and the guide portion and formed from a material having a non-uniform density distribution.

2. The stage apparatus according to claim 1, wherein the predetermined member has a first portion and a second portion that has a higher density than the first portion.

3. The stage apparatus according to claim 1, wherein

the predetermined member includes a first portion and a second portion that is required to have a higher strength than the first portion, and

the density of the second portion is higher than the density of the first portion.

4. The stage apparatus according to claim 3, wherein a screw bush or helisert is provided in the second portion of the predetermined member.

5. The stage apparatus according to claim 1, wherein

the predetermined member includes a first portion and a second portion that is required to have a higher degree of flatness than the first portion;

and

the density of the second portion is higher than the density of the first portion.

6. The stage apparatus according to claim 5, wherein the second portion has a reflecting surface that reflects measuring light for position measurement.

7. The stage apparatus according to claim 5, wherein the second portion has at least one part of portions that are oppositely disposed each other with a gas therebetween so as to form a gas bearing.

8. The stage apparatus according to claim 1, wherein the predetermined member is formed form a porous ceramic or sintered metal.

9. The stage apparatus according to claim 1, wherein the density of the portion of the predetermined member with the lowest density is approximately ½

, ⅓

, ¼

, ⅕

, ⅙

, 1/7, ⅛

, 1/9, 1/10, or 1/20 or less of the density of the portion with the highest density.

10. The stage apparatus according to claim 1, wherein the predetermined member is formed by bake hardening after filling a low-density material in spaces of a frame of high density.

11. The stage apparatus according to claim 1, wherein the material having a non-uniform density distribution is a material whose density continuously changes.

12. An exposure apparatus that exposes a substrate with a pattern that is illuminated by exposure light, comprising a stage apparatus according to claim 1 that drives a mask on which the pattern is formed or the substrate.

13. An exposure apparatus comprising:

an illuminating optical system that irradiates a pattern by exposure light;

a projection optical system in which a substrate is exposed with an image of the pattern via the illuminating optical system; and

a mirror that is provided in the illuminating optical system or the projection optical system, with the density of the portion on which a reflecting surface is formed being higher than the density of the other portion.