Browse Prior Art Database

Optimum Hole Spacing for Positioning Electron Beam Unit

IP.com Disclosure Number: IPCOM000080147D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Ho, HK: AUTHOR [+3]

Abstract

In an electron-beam system designed for use in generating patterns in photoresist in the photolithographic processing of semiconductor wafers, nonlinear deflections of the beam may occur in the operation cycle. A means of compensation for the characteristic drift is provided by replacing the wafer with a calibration grid and monitoring the behavior of the beam, as it sweeps across the grid in raster fashion. To assure high-positional accuracy, a fine mesh grid of n x n holes is used where n is commonly 64 holes or higher. The data generated from this array lead to a high volume of entries into a computer, which is used to control the operation of the electron-beam unit.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Optimum Hole Spacing for Positioning Electron Beam Unit

In an electron-beam system designed for use in generating patterns in photoresist in the photolithographic processing of semiconductor wafers, nonlinear deflections of the beam may occur in the operation cycle. A means of compensation for the characteristic drift is provided by replacing the wafer with a calibration grid and monitoring the behavior of the beam, as it sweeps across the grid in raster fashion. To assure high-positional accuracy, a fine mesh grid of n x n holes is used where n is commonly 64 holes or higher. The data generated from this array lead to a high volume of entries into a computer, which is used to control the operation of the electron-beam unit.

The subject technique provides a method to generate a piecewise optimal set of hole spacings on the grid, for positioning the electron-beam scan to within certain maximum allowable error. After an initial full-field sweep of the grid to obtain a learning curve, subsequent sweeps are analyzed as follows:

Let f(i)(x), i = 1, 2, ..., m represent the m electron-beam scans. f(i) (x) are obtained by curve-fitting and f(i)(x) represent the total error corrections as functions of hold locations.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]