Address

Heidelberg Instruments GmbH
Tullastrasse 2
D-69126 Heidelberg
Germany
Phone: (+49) 6221 34 30 0
Fax:     (+49) 6221 34 30 30
Mail:
Web: www.himt.de

Gray Scale Lithography

With gray scale lithography it is possible to create 3 dimensional microstructures with high quality in a thick layer of photoresist. The fastest and easiest way to do this is with a maskless laser lithography system, which uses an intensity modulated laser beam to write the structures directly into the resist.

The resist is applied to the substrate by spin- or spray-coating and can be several hundred microns thick, but most applications only require a thickness of less than 50 microns. Unsing data from an electronic design, the laser lithography system will expose the resist with a variable dose and the 3 dimensional structures will remain in the resist after the development process.

Gray Scale Process
Gray Scale Process

The final result of this entire process depends on the electronic data, the laser writing and the development, and all of these steps can be independently tuned to produce the best result. This makes it very efficient and economical for product development, as there are no expensive gray tone masks needed in the process.

The gray scale lithography is used for a variety of applications, one of the major ones being micro-optical components like microlenses, diffractive elements or hybrids. The optical structures in the photoresist can subsequently be transferred into the substrate by reactive ion etching or a master for mass production can be created using electroplating.

Lens Lens Grating
Lens Lens Grating
- Pictures Courtesy of IOF -

Heidelberg Instruments is the world leader when it comes to gray scale laser lithography. We not only produce the most sophisticated systems for these applications, but we also have the experience to apply the technology and to help the user achive his goals.