US 6,281,513 B1 · Pattern forming method

Abstract

Forward-scatter energy Ef, deposited at the center of an electron beam focused on a resist film out of energy of a forward-scattered electron, is derived. A first exposure dose Df is also obtained as a minimum exposure dose at which one of lines of a testing resist film starts to leave the center thereof when the testing resist film is developed after the lines have been irradiated with the electron beam with the exposure dose thereof varied. In this case, the resist film for forming a pattern thereon is a negative resist, and has the same composition and thickness as the testing resist film. A line-to-line distance between adjacent ones of the lines gradually increases from a value equal to or smaller than twice the length of a backscattering radius βb to a value more than twice the length of a maximum radius rb of backscattered electron's reach. And a function D(s) of a second exposure dose is obtained using the line-to-line distance as a variable. The second exposure dose is a minimum exposure dose, at which one of spaces between the lines of the testing resist film starts to leave the center thereof. An intensity distribution of energy deposited in a region of the resist film, which is outside of the backscattered electron's reach, is obtained around the center of the focused electron beam by (Df/D(s))×Ef, and used for proximity effect correction.

Claims13

Dependent claims

A method for forming a pattern, comprising the steps of:

depositing a resist film on a film to be processed on a substrate;
irradiating the resist film with an electron beam at an exposure dose controlled by proximity effect correction, thereby writing a pattern onto the resist film;
and
developing the resist film, which has been irradiated with the electron beam, thereby defining a resist pattern,
wherein the proximity effect correction is carried out by using:
a first intensity distribution of energy deposited in the resist film out of energy of a forward-scattered electron caused in the resist film by the irradiation of the electron beam;
a second intensity distribution of energy deposited in the resist film out of energy of a backscattered electron caused in the substrate by the irradiation of the electron beam;
and
a third intensity distribution of energy created by the irradiation of the electron beam and deposited in a region of the resist film, which is outside of a backscattered electron's reach,
the first, second and third intensity distributions being all defined around the center of the electron beam focused.

7 more elements

A method for forming a pattern, comprising the steps of:

depositing a resist film on a film to be processed on a substrate;
irradiating the resist film with an electron beam at an exposure dose controlled by proximity effect correction, thereby writing a pattern onto the resist film;
and
developing the resist film, which has been irradiated with the electron beam, thereby defining a resist pattern,
wherein the proximity effect correction is carried out by using:
a first intensity distribution of energy deposited in the resist film out of energy of a forward-scattered electron caused in the resist film by the irradiation of the electron beam;
a second intensity distribution of energy deposited in the resist film out of energy of a backscattered electron caused in the substrate by the irradiation of the electron beam;
and
a third intensity distribution of energy deposited in a region of the resist film, which is outside of a backscattered electron's reach, out of energy of an X-ray created in the substrate by the irradiation of the electron beam,
the first, second and third intensity distributions being all defined around the center of the electron beam focused.

7 more elements

A method for forming a pattern, comprising the steps of:

a) depositing a resist film on a film to be processed on a substrate;
b) detecting an alignment mark formed on the substrate by scanning an electron beam;
c) irradiating the resist film with the electron beam, thereby writing a pattern onto the resist film;
and
d) developing the resist film, which has been irradiated with the electron beam, thereby defining a resist pattern,
wherein the step c) includes writing the pattern only in a region of the resist film outside of a target region which is outside of the backscattered electron's reach thereof exposed to the electron beam while the electron beam is being scanned in the step b).

3 more elements

A method for forming a pattern, comprising the steps of:

a) depositing a resist film on a film to be processed on a substrate;
b) detecting an alignment mark formed on the substrate by scanning an electron beam;
c) irradiating the resist film with the electron beam, thereby writing a pattern onto the resist film;
and
d) developing the resist film, which has been irradiated with the electron beam, thereby defining a resist pattern,
wherein the step c) includes setting an exposure dose, at which a target region of the resist film is irradiated with the electron beam, smaller than an exposure dose, at which another region of the resist film outside of the target region which is outside of the backscattered electron's reach is irradiated with the electron beam while the electron beam is being scanned in the step b).

3 more elements

Dependencies are inferred from the claim text.

Pattern forming method

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Pattern forming method

Life of this patent

Abstract

Claims13