Browse Prior Art Database

Electron Beam Data Splitting for Electron Beam Projection Mask Making

IP.com Disclosure Number: IPCOM000035868D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Clark, TC: AUTHOR [+2]

Abstract

Two electron beam (EB) projection masks are usually required to generate a single integrated circuit (IC) level to avoid loss of opaque regions which are completely bounded by transmissive (open) regions. Writing EB projection masks with an EB system thus requires splitting data for a complete mask into two sets resulting in a pair of masks having no lost opaque regions. Additionally, in this new technique, data is split between the pair to minimize proximity effects. Higher density of circuit elements or minimization of calculation time for beam parameter adjustment to compensate for proximity is achieved.

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 75% of the total text.

Page 1 of 2

Electron Beam Data Splitting for Electron Beam Projection Mask Making

Two electron beam (EB) projection masks are usually required to generate a single integrated circuit (IC) level to avoid loss of opaque regions which are completely bounded by transmissive (open) regions. Writing EB projection masks with an EB system thus requires splitting data for a complete mask into two sets resulting in a pair of masks having no lost opaque regions. Additionally, in this new technique, data is split between the pair to minimize proximity effects. Higher density of circuit elements or minimization of calculation time for beam parameter adjustment to compensate for proximity is achieved.

Referring to the figure, electron transmission through the hatched regions of pattern A is required to generate a portion of a single IC level using a projection EB mask. To avoid loss of opaque region 2 in the EB projection mask when it is etched, the mask is made in two parts by splitting the data for EB mask writing to make the projection mask into two patterns as shown in patterns B and C. Exposure in an EB projection system to create the pattern of region A in device photoresist is accomplished by first exposing the resist to electrons trans mitted only by the pattern of B, then physically displacing the projection mask to cause electrons subsequently transmitted only through the pattern of C to complete the exposure pattern of region A in the device photoresist. The data to create the ...