Latest News
- April 2010
Talk: Half-tone Proximity Lithography in SUSS Mask Aligner (7716-34)
The Square Conference Ctr., Brussels, Belgium
Wednesday, April 14, 2010, Location: 211/212, Time: 11:40 - 12:00
Authors: Torsten Harzendorf, Lorenz Stürzebecher, Uwe D. Zeitner, Fraunhofer-Institut für Angewandte Optik und Feinmechanik (Germany), Uwe Vogler, Reinhard Voelkel, SUSS MicroOptics SA (Switzerland);
Abstract: The half-tone lithography using pixelated chromium masks in a projection stepper is an established technology in micro-optics fabrication. However, the projection lithography tool is comparably expensive and the achievable lateral resolution is typically limited.
By using pixel diffraction effects, binary and continuous profile lithography with submicron resolution can be installed on a conventional mask aligner. To achieve this goal the control of both, the angular spectrum of the illumination and the mask features is essential. We used a novel micro-optics based illumination system referred as "MO Exposure Systems" in a SUSS MA6 mask aligner for the dedicated shaping of the angular illumination distribution. In combination with an adapted lithography mask the formation of a desired intensity distribution in the resist layer is possible. A general mathematic model describes the relation between the angular spectrum of the mask illumination, pixel size and pitch in the mask, proximity distance and propagated field, which also includes special cases like Talbot imaging. We show that a wide range of different micro-optical structures can be optimized by controlling the light diffraction in proximity lithography. Parameter settings will be found for submicron binary pattern up to continuous profile structures with extensions up to several tens of microns. An additional interesting application of this approach is the combination of binary and continuous profiles in single elements, e.g. lens segments or lenses with diffractive correction or AR structures. Experimental results achieved for different structure types, like high aspect ratio holes, blazed gratings with a period smaller than 2 microns and arbitrary shaped lens arrays will be presented.
- March 2010SUSS now introduces Source-Mask Optimization for Mask Aligner Lithography. Source-Mask Optimization (SMO) is a photolithography enhancement technique commonly used in optical lithography to compensate for image errors due to diffraction and process effects. Source-Mask Optimization comprises different measures like Customized Illumination, Optical Proximity Correction (OPC), Polarized Phase Shift Masks (P:PSM) and Resolution Enhancement Techniques (RET). Primary goals are to improve CD control, increase resolution and depth of focus (DOF), improve manufacturability and enlarge the process window.
-
- June 2009SUSS MicroTec launches with the MO Exposure Optics a new illumination system designed for all generations of manual and automatic SUSS mask aligners. The new optics is based on unique and high quality microlens arrays to provide higher intensity, improved exposure light uniformity and customized illumination shaping to further optimize the process window and yield in contact and proximity lithography. MO Exposure Optics (patent pending) has been exclusively developed by SUSS MicroOptics.
-
