US 5,633,713 A · Method and system for evaluating distribution of absorption light amount in optical lithography

Abstract

A system for evaluating a distribution of an absorption light amount in a resist comprises a diffractive light intensity distribution calculating unit for calculating a diffractive light intensity distribution on a plane of a pupil of a projection exposing apparatus, a light absorption rate calculating unit for calculating, on the basis of an incidence angle and a thin-film interference effect of each of diffractive light intensity components of the diffractive light intensity distribution passing through the pupil and being incident on a wafer surface of the projection exposing apparatus, a light absorption rate of each of the diffractive light intensity components in a resist of the projection exposing apparatus, a weight calculating unit for calculating a weight of each diffractive light intensity component, on the basis of the light absorption rate of each diffractive light intensity component calculated by the light absorption rate calculating unit, a multiplying unit for multiplying each diffractive light intensity component of the diffractive light intensity distribution by the weight of each diffractive light intensity component calculated by the weight calculating unit, and an integrating unit for integrating, in the plane of the pupil, each diffractive light intensity component multiplied with the weight obtained by the multiplying unit, thereby obtaining an absorption light amount distribution in the resist.

Claims15

Dependent claims

A system for evaluating a distribution of an absorption light amount in a resist, said system comprising:

diffractive light intensity distribution calculating means for calculating a diffractive light intensity distribution on a plane of a pupil of a projection exposing apparatus;
light absorption rate calculating means for calculating, on the basis of an incidence angle and a thin-film interference effect of each of diffractive light intensity components of said diffractive light intensity distribution passing through said pupil and being incident on a wafer surface of said projection exposing apparatus, a light absorption rate of each of the diffractive light intensity components in a resist of said projection exposing apparatus;
weight calculating means for calculating a weight of each diffractive light intensity component, on the basis of the light absorption rate of each diffractive light intensity component calculated by said light absorption rate calculating means;
multiplying means for multiplying each diffractive light intensity component of the diffractive light intensity distribution by the weight of each diffractive light intensity component calculated by said weight calculating means;
and
integrating means for integrating, in the plane of the pupil, each diffractive light intensity component multiplied with the weight obtained by said multiplying means, thereby obtaining an absorption light amount distribution in the resist.

3 more elements

A system for evaluating a distribution of an absorption light amount in a resist, said system comprising:

diffractive light intensity distribution calculating means for calculating a diffractive light intensity distribution on a plane of a pupil of a projection exposure apparatus on the basis of a numerical aperture, an exposure wavelength, a secondary light source shape and a mask pattern of the projection exposing apparatus;
light amount ratio calculating means for calculating a ratio of a light amount absorbed in a resist of each of diffractive light intensity components of the diffractive light intensity distribution calculated by said diffractive light intensity distribution calculating means;
modulating means for modulating a complex amplitude distribution of the diffractive light intensity in the plane of the pupil in accordance with the light amount ratio calculated by said light amount ratio calculating means;
and
execution means for executing a partially coherent imaging calculation on the basis of the complex amplitude distribution of the diffractive light intensity modulated by said modulating means, thereby obtaining an absorption light amount distribution in the resist.

2 more elements

A method of evaluating a distribution of an absorption light amount in a resist, said method comprising:

a diffractive light intensity distribution calculating step of calculating a diffractive light intensity distribution on a plane of a pupil of a projection exposing apparatus;
a light absorption rate calculating step of calculating, on the basis of an incidence angle and a thin-film interference effect of each of diffractive light intensity components of said diffractive light intensity distribution passing through said pupil and being incident on a wafer surface of said projection exposing apparatus, a light absorption rate of each of the diffractive light intensity components in a resist of said projection exposing apparatus;
a weight calculating step of calculating a weight of each diffractive light intensity component, on the basis of the light absorption rate of each diffractive light intensity component calculated in said light absorption rate calculating step;
a multiplying step of multiplying each diffractive light intensity component of the diffractive light intensity distribution by the weight of each diffractive light intensity component calculated in said weight calculating step;
and
an integrating step of integrating, in the plane of the pupil, each diffractive light intensity component multiplied with the weight obtained in said multiplying step, thereby obtaining an absorption light amount distribution in the resist.