Browse Prior Art Database

Linewidth Measurement Standard Fabrication Method

IP.com Disclosure Number: IPCOM000037780D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-30
Document File: 1 page(s) / 13K

Publishing Venue

IBM

Related People

Rosenfield, MG: AUTHOR

Abstract

A technique is described whereby a linewidth measurement standard for scanning electron microscope (SEM) metrology can be fabricated using electon-beam lithography. The resist used should be able to withstand repeated exposures to vacuum and electron beams after development.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 1

Linewidth Measurement Standard Fabrication Method

A technique is described whereby a linewidth measurement standard for scanning electron microscope (SEM) metrology can be fabricated using electon- beam lithography. The resist used should be able to withstand repeated exposures to vacuum and electron beams after development.

Typically, the patterns which make up a linewidth standard should consist of isolated lines of resist, isolated spaces and line/space arrays, since different resist structures generate different signals in the SEM. Several different feature sizes should be included in the standard, such as 0.25, 0.5, 1.0 and 2.5 mm. The patterns should also be long enough and isolated from one another so that all patterns on a wafer are in the same environment, as far as electron scattering during exposure is concerned. In this way, all features of a particular type will receive the same dose and exposure, after the electron-beam proximity effect is taken into account, and corrected when required.

The basic process consists of exposing the wafer patterns as long features, generally 800 mm, using a vector scan electron- beam lithography system. Approximately 10-40 of the features are exposed in a staggered fashion so that upon cross-sectioning, 10-20 cross-sections of each feature would be available for calibration. The patterns are exposed exactly parallel to a crystal plane, so that the resist cross-sections are exactly perpendicular to the feature.

After cross-sectioning the patterns, one-half of the sample is coated with a thin (0.005 mm) layer of conducting Au/Pd, or carbon, and measured in...