# US 7,608,845 B2 · Charged particle beam writing apparatus and method thereof, and method for resizing dimension variation due to loading effect

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,608,845 B2
- Document ID: US7608845B2
- Status: Granted
- Kind: B2
- Application number: 11/942,307
- Filed: 2007-11-19
- Published: 2008-07-31
- Granted: 2009-10-27
- Earliest claimed: 2006-11-29
- Assignees: NuFlare Technology, Inc.
- Inventors: Takayuki Abe; Junichi Suzuki; Tomohiro Iijima; Hideyuki Tsurumaki
- Web page: https://patentgrep.com/patent/US7608845B2

## CPC

- H01J 37/3174: {Particle-beam lithography, e.g. electron beam lithography}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- B82Y 40/00: Manufacture or treatment of nanostructures
- H01J 2237/004: Charge control of objects or beams
- H01J 2237/30455: Correction during exposure
- Y10S 430/143: Electron beam
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A charged particle beam writing apparatus includes a first part configured, based on pattern data, to estimate a total writing time, a second part configured to acquire a base dose at an arbitrary time, after writing start time and within the total writing time by using a first correlation among a time having passed since the writing start time, the total writing time, and the base dose, a third part configured to acquire a fogging effect correction coefficient at the arbitrary time by using a second correlation among the time, the total writing time and the coefficient, a forth part configured to calculate a beam dose at the arbitrary time by using the base dose and the coefficient, a fifth part configured to calculate a beam irradiation time based on the beam dose, a deflector for deflecting the beam, and an aperture for blocking the beam.

## Claims

### Claim 1

A charged particle beam writing apparatus comprising:
a writing time estimation calculating part configured, based on pattern data to be written in a writing region, to estimate a total writing time for writing a pattern based on the pattern data with a charged particle beam;
a base dose acquiring part configured to acquire a base dose at an arbitrary time, after writing start time and within the total writing time, in writing using the pattern data, by using a first correlation among a time having passed since the writing start time, the total writing time, and the base dose;
a fogging effect correction coefficient acquiring part configured to acquire a fogging effect correction coefficient at the arbitrary time, in writing using the pattern data, by using a second correlation among the time having passed since the writing start time, the estimated total writing time and the fogging effect correction coefficient;
a beam dose calculating part configured to calculate a beam dose at the arbitrary time by using the base dose and the fogging effect correction coefficient;
a beam irradiation time calculating part configured to calculate a beam irradiation time of the charged particle beam at a position in the writing region, based on a calculated beam dose;
a deflector configured to deflect the charged particle beam according to the beam irradiation time; and
an aperture configured to block the charged particle beam deflected by the deflector.

### Claim 2 (depends on 1)

The writing apparatus according to claim 1, wherein the first correlation is obtained based on a first coefficient parameter and a relation between a pattern line width and the base dose, wherein the first coefficient parameter is obtained based on a relation between an elapsed time after writing and the base dose for correcting the pattern line width which varies depending upon the elapsed time.

### Claim 3 (depends on 1)

The writing apparatus according to claim 1, wherein the second correlation is obtained based on a second coefficient parameter and a relation between a pattern line width and the fogging effect correction coefficient, wherein the second coefficient parameter is obtained based on a relation between an elapsed time after writing and the fogging effect correction coefficient for correcting the pattern line width which varies depending upon the elapsed time.

### Claim 4

A charged particle beam writing apparatus comprising:
a writing time estimation calculating part configured, based on pattern data to be written in a writing region, to estimate a total writing time for writing the pattern data with a charged particle beam;
a loading effect correction coefficient acquiring part configured to acquire a loading effect correction coefficient at an arbitrary time, after writing start time and within the total writing time, in writing using the pattern data, by using a correlation among a time having passed since the writing start time, the total writing time, and the loading effect correction coefficient;
a dimension variation amount calculating part configured to calculate a dimension variation amount due to a loading effect at the arbitrary time by using the loading effect correction coefficient;
a beam dose acquiring part configured to acquire a beam dose at the arbitrary time based on the dimension variation amount;
a beam irradiation time calculating part configured to calculate a beam irradiation time of the charged particle beam at a position in the writing region, based on a acquired beam dose;
a deflector configured to deflect the charged particle beam according to the beam irradiation time; and
an aperture configured to block the charged particle beam deflected by the deflector.

### Claim 5

A charged particle beam writing method comprising:
inputting pattern data to be written in a writing region;
estimating a total writing time for writing a pattern based on the pattern data;
acquiring a base dose at an arbitrary time, after writing start time and within the total writing time, in writing using the pattern data, by using a first correlation among a time having passed since the writing start time, the total writing time, and the base dose;
acquiring a fogging effect correction coefficient at the arbitrary time, in writing using the pattern data, by using a second correlation among the time having passed since the writing start time, the total writing time and the fogging effect correction coefficient;
calculating a beam dose at the arbitrary time by using the base dose and the fogging effect correction coefficient; and
writing a position in the writing region with the charged particle beam, according to the beam dose.

### Claim 6 (depends on 5)

The writing method according to claim 5, wherein the first correlation is obtained based on a first coefficient parameter and a relation between a pattern line width and the base dose, wherein the first coefficient parameter is obtained based on a relation between an elapsed time after writing and the base dose for correcting the pattern line width which varies depending upon the elapsed time.

### Claim 7 (depends on 5)

The writing method according to claim 5, wherein the second correlation is obtained based on a second coefficient parameter and a relation between a pattern line width and the fogging effect correction coefficient, wherein the second coefficient parameter is obtained based on a relation between an elapsed time after writing and the fogging effect correction coefficient for correcting the pattern line width which varies depending upon the elapsed time.

### Claim 8

A charged particle beam writing method comprising:
estimating a total writing time for writing a pattern to be written in a writing region, based on a pattern data;
acquiring a loading effect correction coefficient at an arbitrary time, after writing start time and within the total writing time, in writing using the pattern data, by using a correlation among a time having passed since the writing start time, the total writing time, and the loading effect correction coefficient;
calculating a dimension variation amount due to the loading effect at the arbitrary time by using the loading effect correction coefficient;
obtaining a beam dose at the arbitrary time based on the dimension variation amount; and
writing a position in the writing region with the charged particle beam, according to the beam dose.

### Claim 9

A method for resizing a dimension variation amount comprising:
estimating a total writing time for writing a pattern to be written in a writing region, based on a pattern data;
acquiring a loading effect correction coefficient at an arbitrary time, after writing start time and within the total writing time, in writing using the pattern data, by using a correlation among a time having passed since the writing start time, the total writing time, and the loading effect correction coefficient;
calculating a dimension variation amount due to the loading effect at the arbitrary time by using the loading effect correction coefficient; and
resizing the pattern data according to an estimated time to be passed since the writing start time, based on the dimension variation amount and outputting resized pattern data.