US 6,641,981 B1 · Exposure method, exposure apparatus, and device manufacturing method

Abstract

In projecting a pattern formed on a mask onto a substrate by using a progressive focus exposure method and transferring/forming an image of the pattern on a substrate, a control unit changes the distribution of energy amounts supplied onto the substrate based on the relative positions of the imaging plane and the substrate surface, and the integrated energy amount supplied onto the substrate in accordance with the position of an irradiation area on the substrate surface which is irradiated with an energy beam through the projection optical system. With this operation, in accordance with information about the distribution of variations in resist layer thickness on the substrate, which is obtained in advance, at least one of the distribution of energy amounts and the integrated energy, which reduce the influences of this distribution, can be changed. As a consequence, the depth of focus of the projection optical system can be substantially increased, and variations in the shapes of pattern images formed on a substrate can be suppressed.

Claims26

Dependent claims

An exposure method of irradiating a mask on which a pattern is formed with an energy beam;

and changing a positional relationship between an imaging plane of a projection optical system and a substrate in an optical axis direction of said projection optical system according to a predetermined procedure so that an irradiation area on a substrate surface irradiated with said energy beam through said projection optical system is always located in a range having a predetermined width in said optical axis direction and including said imaging plane, and a distribution of energy supplied onto said substrate surface in the optical axis direction becomes a desired distribution, thereby transferring said pattern onto said substrate, said method comprising:
obtaining a plurality of energy distributions in the optical axis direction in accordance with a position on said substrate of said area and storing the plurality of energy distributions in advance;
and
transferring said pattern onto said substrate, wherein the distribution of energy is changed in accordance with the position on said substrate of said area based on said plurality of energy distributions stored in advance.

1 more element

An exposure method of irradiating a pattern with an energy beam and changing a positional relationship between an imaging plane of a projection optical system and a substrate in an optical axis direction of said projection optical system according to a predetermined procedure so that an irradiation area on a substrate surface irradiated with said energy beam through said projection optical system is always located in a range having a predetermined width in said optical axis direction and including said imaging plane, and a distribution of energy supplied onto said substrate surface with respect to a position of said substrate surface with datum to said imaging plane becomes a desired distribution, thereby transferring said pattern onto said substrate, said method comprising:

preparing a plurality of patterns;
obtaining a plurality of energy distributions in the optical axis direction in accordance with said plurality of patterns subject to transfer and storing said plurality of energy distributions in advance;
and
transferring each of said plurality of patterns onto said substrate,
wherein the distribution of energy is changed in accordance with a pattern subject to transfer based on said plurality of energy distributions stored in advance, upon transferring each of said plurality of patterns onto said substrate.

2 more elements

Dependencies are inferred from the claim text.

Exposure method, exposure apparatus, and device manufacturing method

Life of this patent

Exposure method, exposure apparatus, and device manufacturing method

Life of this patent

Abstract

Claims26