Micronic, Fraunhofer Join in Patterning Effort.

A collaboration between Micronic Laser Systems AB (P.O. Box 3141, Taby, Sweden) and the Fraunhofer Institute for Microelectronic Circuits and Systems (Dresden, Germany) will result in a new breed of pattern generators for future generations of semiconductor products. Building on its established position as a technology leader for high-end pattern generators for TFT and other displays, Micronic is entering the market for pattern generators with systems based on their current laser scanning technology targeting the 0.18 micron design node. A new DUV-SLM technology will be used for future design nodes.

Micronic concluded that to follow the International Technology Roadmap for Semiconductors (ITRS), a completely new writing technology was needed. No system that uses a limited number of scanning beams will, in the long run, be able to cope with the ever-increasing amount of pattern detail that results from shrinking feature sizes and more complex mask technology. The number of features in a reticle has increased by a factor of 300 over the past 10 years and will continue its rapid increase as long as Moore's law holds.

The new spatial light modulator (SLM) technology, building on developments at Fraunhofer since the late 1980s, provides a way to increase the writing speed by exposing a million pixels or more in parallel. The spatial light modulator is a semiconductor chip with an array of micromirrors, each of which can be set to a reflecting or nonreflecting state by the application of an electric field. The pattern generator is built similar to a modern stepper with a pulsed excimer laser and a scanning stage. The SLM takes the place of the mask, but the reduction ratio is much larger so that each pixel is imaged as a 0.1 0.1 micron image element.

Each exposure flash prints a projected image of the SLM in the photoresist on the mask blank. Before the next flash, ...