Share Email Print

Optical Engineering

X-Ray Lithography Applied To The Fabrication Of One Micrometer N-Channel Metal Oxide Semiconductor Circuits
Author(s): E. N. Fuls
Format Member Price Non-Member Price
PDF $20.00 $25.00

Paper Abstract

A full-field x-ray exposure system based on a 4 kW stationary palladium source emitting the 4.37 A La line has been developed and evaluated in the fabrication of silicon integrated circuits. It has been used successfully in the patterning of 1 um design rule high performance n-channel metal oxide semi-conductor (NMOS) circuits of various complexities from ring oscillators to large scale custom logic and memory devices. A shadow mask consisting of a 6µm boron nitride membrane and 0.7 pm gold-tantalum features is used to transfer patterns into a chlorine-based x-ray resist sensitive to the 4.37 A radiation. Pattern transfer to the silicon surface is faithfully reproduced through the use of a trilevel structure and anisotropic reactive ion etching. Alignment of various levels is accomplished optically through the use of a bifocal, split-field microscope at high magnification and the use of dark-field edge sensing for improved contrast. Linewidth control and registration data are presented for various NMOS circuit patterns.

Paper Details

Date Published: 1 April 1983
PDF: 4 pages
Opt. Eng. 22(2) 222199 doi: 10.1117/12.7973082
Published in: Optical Engineering Volume 22, Issue 2
Show Author Affiliations
E. N. Fuls, Bell Laboratories (United States)

© SPIE. Terms of Use
Back to Top