Browse Prior Art Database

Scanning X-Ray Lithography

IP.com Disclosure Number: IPCOM000048615D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Chaput, J: AUTHOR [+3]

Abstract

With ever increasing integration densities. VLSI chips require improved lithography techniques, and among the most promising is X-ray lithography. X-ray lithography appears to be a low cost, high throughput alternative in all respects. Different X-ray sources may be used; however, synchrotron radiation has often been suggested as an ideal X-ray source, since it provides highly energetic and well collimated X-ray radiation. Unfortunately, with present X-ray lithography systems using synchrotron radiation, a trade-off between high throughput and good exposure uniformity is to be made. As a matter of fact, the vertical (or transversal) distribution of a synchrotron radiation is gaussian, and rotating the anode beam has a similar characteristic.

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 77% of the total text.

Page 1 of 2

Scanning X-Ray Lithography

With ever increasing integration densities. VLSI chips require improved lithography techniques, and among the most promising is X-ray lithography. X- ray lithography appears to be a low cost, high throughput alternative in all respects. Different X-ray sources may be used; however, synchrotron radiation has often been suggested as an ideal X-ray source, since it provides highly energetic and well collimated X-ray radiation. Unfortunately, with present X-ray lithography systems using synchrotron radiation, a trade-off between high throughput and good exposure uniformity is to be made. As a matter of fact, the vertical (or transversal) distribution of a synchrotron radiation is gaussian, and rotating the anode beam has a similar characteristic. Thus, a silicon wafer coated with an X-ray sensitive resist, exposed to a synchrotron X-ray beam, provides symmetrical attenuation of the beam. In order to get perfect exposure uniformity, it is therefore recommended to mechanically scan the wafer in front of the standing X-ray beam. The figure depicts schematically how this solution may be implemented. Inside the vacuum chamber, sliding means, typically a lead screw, allows the wafer to move perpendicularly to the beam like a 1.1 scanning projection printer.

As a typical beam width of synchrotron radiation is 150 mm, the scanning travel is unlimited. As a result, wafers up to 6 inches can be processed using this technique. The advantages of this t...