Gap adjustment apparatus and gap adjustment method for adjusting gap between two objects

• US 6,852,988 B2
• Filed: 11/27/2001
• Issued: 02/08/2005
• Est. Priority Date: 11/28/2000
• Status: Expired due to Fees

• Current Assignee: Sumitomo Heavy Industries Limited
• Original Assignee: Sumitomo Heavy Industries Limited
• Inventors: Li, Xuan
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US09/993,500
• Publication Number:
  US 20020063221A1
• Time in Patent Office: 1,169 Days
• Field of Search: 738658-8659, 73/17.9, 734/321, 250/491.1, 702/158, 269/45, 378204-205, 378207-208, 324/671, 324/686, 324/690, 324/662, 324/207.15, 700302-303, 700117-121, 700192-193, 700/195
• US Class Current: 250/491.1
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 7/7035 Proximity or contact printers
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: H01J 37/3174 Particle-beam lithography, e.g. electron beam lithography
• CPC Class Codes: H01L 21/682 Mask-wafer alignment in general G03F7/70, G03F9/70

Abstract

A first stage and a second stage are disposed to face each other. A first object is fixed on the first stage. A first displacement sensor attached on the first stage is used to measure a distance extending from the first displacement sensor to a plane disposed in front of the first displacement sensor. A second object is fixed on the second stage. A second displacement sensor attached on the second stage is used to measure a distance extending from the second displacement sensor to a plane disposed in front of the second displacement sensor. A moving mechanism is provided to move one of the first stage and the second stage, with the movement of one stage being relative to the other stage.

Claims

1. A gap adjustment apparatus comprising:

a first holder for holding a first object having a first measurement surface;

a second holder for holding a second object having a second measurement surface, in a manner such that the second measurement surface faces the first measurement surface;

a first displacement gauge for measuring a distance extending from the first displacement gauge to the first measurement surface;

a target whose relative position with respect to the first displacement gauge is fixed, the target having a target measurement surface orientated in the same direction as the second measurement surface;

a second displacement gauge for measuring distances extending from the second displacement gauge to the second measurement surface and to the target measurement surface; and

a moving mechanism for moving the first holder and the second holder to alter a gap between the first measurement surface and the second measurement surface,

wherein when the gap between the first measurement surface and the second measurement surface is altered, a gap between the second displacement gauge and the target measurement surface is not altered.

2. A gap adjustment apparatus according to claim 1, wherein the first displacement gauge and the second displacement gauge are all electrostatic capacity type displacement gauges.

3. A gap adjustment apparatus comprising:

a first holder for holding a first object having a first measurement surface;

a second holder for holding a second object having a second measurement surface, in a manner such that the second measurement surface faces the first measurement surface;

a first displacement gauge for measuring a distance extending from the first displacement gauge to the first measurement surface;

a target whose relative position with respect to the first displacement gauge is fixed, the target having a target measurement surface orientated in the same direction as the second measurement surface;

a second displacement gauge for measuring distances extending from the second displacement gauge to the second measurement surface and to the target measurement surface; and

a moving mechanism for moving at least one of the first holder and the second holder, in order to alter a gap between the first measurement surface and the second measurement surface,

wherein the first displacement gauge is disposed on the outside of a displacement amount detectable range of the second displacement gauge, the second displacement gauge is disposed on the outside of a displacement amount detectable range of the first displacement gauge.

4. A gap adjustment apparatus comprising:

a first holder for holding a first object having a first measurement surface;

a second holder for holding a second object having a second measurement surface, in a manner such that the second measurement surface faces the first measurement surface;

a first displacement gauge for measuring a distance extending from the first displacement gauge to the first measurement surface;

a target whose relative position with respect to the first displacement gauge is fixed, the target having a target measurement surface orientated in the same direction as the second measurement surface;

a second displacement gauge for measuring distances extending from the second displacement gauge to the second measurement surface and to the target measurement surface;

a moving mechanism for moving at least one of the first holder and the second holder, in order to alter a gap between the first measurement surface and the second measurement surface; and

a controller capable of driving the moving mechanism in accordance with a calculation result calculated by using an equation D_A+D_D−

(D_B+D_C) in which D_A is a distance extending from the second displacement gauge to the second measurement surface, D_B is a distance extending from the second displacement gauge to the target measurement surface, D_C is a distance extending from the first displacement gauge to the target measurement surface, D_D is a distance extending from the first displacement gauge to the first measurement surface.

5. A gap adjustment apparatus comprising:

a first holder for holding a first object having a first measurement surface;

a second holder for holding a second object having a second measurement surface, in a manner such that the second measurement surface faces the first measurement surface;

a first displacement gauge for measuring a distance extending from the first displacement gauge to the first measurement surface;

a target whose relative position with respect to the first displacement gauge is fixed, the target having a target measurement surface orientated in the same direction as the second measurement surface;

a second displacement gauge for measuring distances extending from the second displacement gauge to the second measurement surface and to the target measurement surface; and

a moving mechanism for moving at least one of the first holder and the second holder, in order to alter a gap between the first measurement surface and the second measurement surface,

wherein one of first object and the second object is a mask for use in the electron beam proximity exposure, the other of the first object and the second object is a wafer to be subjected to the exposure treatment, the apparatus further comprising;

an electron gun for emitting an electron beam; and

an electron beam controller for controlling the electron beam, in a manner such that the electron beam emitted from the electron gun is enabled to pass through the mask so as to irradiate the wafer.