Method of correcting projection optical system and method of manufacturing semiconductor device

• US 20020001071A1
• Filed: 06/29/2001
• Published: 01/03/2002
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Toshiba Memory Corporation (Kioxia Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takakuwa, Manabu, Nomura, Hiroshi, Konomi, Kenji
• Granted Patent: US 6,741,327 B2
• Time in Patent Office: Days
• US Class Current: 355/52
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• CPC Class Codes: G03F 7/706 Aberration measurement

Abstract

The method of correcting a residual aberration of a projection optical system, which is used for projecting a pattern of a photo mask onto a photosensitive film located on a substrate, the method includes calculating an effect of a residual aberration on a given pattern on the basis of the residual aberration of the projection optical system obtained by measurement, calculating a moving amount of an adjustable aberration in the projection optical system such that the effect of the residual aberration becomes minimum in a given area, and moving the adjustable aberration in accordance with the calculated moving amount.

Claims

1. A method of correcting a residual aberration of a projection optical system, which is used for projecting a pattern of a photo mask onto a photosensitive film located on a substrate, said method comprising:

calculating an effect of a residual aberration on a given pattern on the basis of the residual aberration of the projection optical system obtained by measurement;

calculating a moving amount of an adjustable aberration in the projection optical system such that the effect of the residual aberration becomes minimum in a given area; and

moving the adjustable aberration in accordance with the calculated moving amount.

2. A method according to claim 1, further comprising measuring the adjustable aberration moved.

3. A method according to claim 1, wherein the effect of the residual aberration is calculated with use of coefficients of a Zernike polynomial.

4. A method according to claim 1, wherein the moving amount is calculated by imaginarily varying the adjustable aberration.

5. A method of manufacturing a semiconductor device, comprising:

correcting a residual aberration of a projection optical system, using the method according to claim 1; and

projecting a pattern of a photo mask onto a photosensitive film located on a semiconductor substrate by the projection optical system.