Adresse

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

Optische Komponenten

The optical components and their setup are the key to the performance of the Heidelberg Instruments Lithography Systems, defining the resolution and throughput of the different systems. In all our systems the optics are choosen according to the Laser that is installed in the system, and off the shelf components are used as much as possible. This way new components and new technologies can be integrated easily into the systems.

Included in the optical setup is a metrology and alignment system offering two cameras, which can be used to perform a variety of measurement tasks and also to align new exposures to existing structures on the substrate. The macro camera has a large field of view and is used to locate structures on the substrate and for more accurate measurements and alignment a high resolution micro camera is used.

The systems use a raster scan technology to expose the substrate, no matter whether you are writing binary exposures or complex 3-dimensional structures. The write time of a specific design does also not depend on the fill factor of the structures as in a vector scan technology, but only on the overall area of the design.

Main advantages of the optical design are:

  • all optical components remain fixed, ensuring high quality exposures
  • the optical system is optimized for the wavelength of the laser source
  • lenses are treated with an anti-reflex coating to minimize reflections and maximize transparency
  • mirrors are dielectric to minimize the loss of energy

The majority of our systems use acousto-optic modulators and deflectors to control the laser intensity and to scan the beam. The following picture illustrates the exposure principle. The AOM modulates the laser beam intensity while the AOD deflects the beam and is performing a fast scan perpendicular to the moving substrate. This way stripes are exposed on the substrate that have the width of a scan. By stitching multiple stripes together the entire substrate is exposed.

Writing Strategy
Writing Strategy

This writing strategy with a modulated and scanned beam is basically the same for all systems, but there are different levels of this setup. By increasing the complexity of the optical setup in our larger systems, it is possible to increase the throughput significantly, making it possible to write large masks in a short period of time. In addition, the systems offer a number of Write Modes that use modified optical setups to provide different resolutions and write speeds. The user of the system can easily switch between these modes to optimize the performance of the system for individual exposures.

For even higher throughput we developed a new and patented exposure technology, realized for the first time in our new VPG line of lithography systems. In the optical setup of these systems the modulator and deflector technology is replaced be a spatial light modulator, which is capable of modulating a large number of pixels in parallel. This new optical setup enables the system to do high quality exposures with an extreme throughput.