A new '2D to 3D' X-ray lithography technology for gray scale structures

A new '2D to 3D' technology for gray scale structure production developed originally for e-beam lithography is successfully extended to X-ray lithography. A two-dimensional binary structure with a specially designed topology produced in a positive resist can be transformed into a three-dimensional binary structure by resist reflowing during baking at a temperature higher than the glassing temperature for this resist. Based on the binary nature of the lithography process, this technology demonstrates much higher process latitude and a possibility of resist structure formation with 20-40 different heights in a relatively thick resist layer. (C) 2001 Elsevier Science B.V. All rights reserved.