Optical exposure method

• US 6,045,976 A
• Filed: 10/25/1996
• Issued: 04/04/2000
• Est. Priority Date: 06/02/1992
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Tanaka, Hiroyuki, Taguchi, Masao, Asai, Satoru, Nakagawa, Kenji, Hanyu, Isamu, Haruki, Tamae
• Primary Examiner(s): Nguyen, Nam
• Assistant Examiner(s): VERSTEEG, STEVEN H
• Application Number:
  US08/734,790
• Time in Patent Office: 1,257 Days
• Field of Search: 430/396, 430/5, 430/311, 250/492.22, 250/492.23
• US Class Current: 430/311
• CPC Class Codes: G03F 7/201 characterised by an oblique exposure; characterised by the use of plural sources; characterised by the rotation of the optical device; characterised by a relative movement of the optical device, the light source, the sensitive system or the mask
• CPC Class Codes: G03F 7/70091 Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
• CPC Class Codes: G03F 7/701 Off-axis setting using an aperture
• CPC Class Codes: G03F 7/70125 Use of illumination settings tailored to particular mask patterns details of setting means G03F7/70091
• CPC Class Codes: G03F 7/70241 Optical aspects of refractive lens systems, i.e. comprising only refractive elements
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• CPC Class Codes: G03F 7/70566 Polarisation control
• CPC Class Codes: G03F 7/70583 Speckle reduction, e.g. coherence control or amplitude/wavefront splitting

Abstract

An optical exposure method in photolithography applied for precise processing when semiconductor devices are produced. A pattern on a photomask is projected and exposed on a register on a base plate with an exposure device including a deformation illumination system, a photomask and a projection lens. The deformation illumination system is composed of a light source, a diaphragm and a condenser lens, and the diaphragm is provided with a linear through-hole. The optical exposure method uses a ray of linear light for illumination or two rays of linear light for illumination that are parallel with the pattern. The two rays of linear light are symmetrical with respect to an optical axis. These rays are parallel with the pattern in a position separate from the optical axis of the exposure device when the photomask pattern is a line and space pattern.

Claims

1. Projection forming method to transfer a mask pattern, in which a profile long in one direction is repeatedly formed so that a line and space pattern is formed by exposure to light, which is linearly polarized in a longitudinal direction of the line of said line and space pattern, using a projection lens.

2. The projection forming method according to claim 1, wherein said pattern is a phase shift mask pattern.

3. The projection forming method according to claim 1, wherein said exposure light is projected to said profile in such a manner that an incident surface of said exposure light is perpendicular to the direction of the line of the line and space pattern, and the primary direction of said exposure light is oblique on said incident surface.

4. A projection forming method comprising the steps of:

providing a mask having a pattern with a long profile extending in one direction so that a line and space pattern is formed;

providing a polarized light, which is linear in a longitudinal direction of the line of said line and space pattern;

exposing said mask to said light; and

transferring said pattern of said mask onto a resist on a wafer using a projection lens.