Fraunhofer IPMS has developed a one-dimensional high-speed spatial light modulator in cooperation with Micronic Mydata AB. This SLM is the core element of the Swedish company's new LDI 5sp series of Laser-Direct-Imaging systems optimized for processing of advanced substrates for semiconductor packaging. This paper reports on design, technology, characterization and application results of the new SLM. With a resolution of 8192 pixels that can be modulated in the MHz range and the capability to generate intensity gray-levels instantly without time multiplexing, the SLM is applicable also in many other fields, wherever modulation of ultraviolet light needs to be combined with high throughput and high precision.

We describe charging effects on spatial light modulators (SLM). These light modulators consist of up to one million mirrors that can be addressed individually and are operated at a frame rate of up to 2 kHz. They are used for deep ultraviolet (DUV) mask writing where they have to meet very high requirements with respect to accuracy. To be usable in a mask-writing tool, the chips have to be able to work under DUV light and maintain their performance with high accuracy over a long period of time. Charging effects are a problem frequently encountered with MEMS, especially when they are operated in an analog mode. In this work, the issue of charging effects in SLMs used for microlithography, their causes and methods of their reduction or elimination, by means of addressing methods as well as technological changes, is discussed. The first method deals with the way charges can accumulate within the actuator. It is a simple method that requires no technological changes but cannot always be implemented. The second involves the removal of the materials within the actuator where charges can accumulate

The Fraunhofer Institute for Photonic Microsystems (IPMS) develops and fabricates MOEMS micro-mirror arrays for a variety of applications in image generation, wave-front correction and pulse shaping. In an effort to extent the application range, mirrors are being developed that withstand higher light intensities. The absorbed light generates heat. Being suspended on thin hinges, and isolated from the bulk by an air gap, the mirrors heat up. Their temperature can be significantly higher than that of their substrate. In this paper we describe an experiment carried out to verify simulations on the temperature within the mirror plates during irradiation. We created a structure out of electrically connected mirror plates forming a four-point electrical resistor, and calibrated the thermal coefficient of the resistor in a temperature chamber. We irradiated the resistor and calculated the mirror temperature. In the experiment, the temperature in the mirror plates increased by up to 180 °C. The mirrors did not show significant damage despite the high temperatures. Also, the experiment confirms the choice of heat transport mechanisms used in the simulations. The experiment was done on 48 ?m x 48 ?m mirrors suspended over a 5 ?m air gap, using a 355 nm solid-state laser (4 W, up to 500 W/cm²)

An innovative instrument for fast and accurate surface profiling of three dimensional patterned microstructures and insitu plasma etching depth control is proposed. Several advantages of the design make it promising for in-situ metrology. First, the system constitutes a common-path interferometer with the spatial phase shift between the reference and the object beams, thus the vibration and improper positioning of an object have a minor impact on the system performance. Second, no mechanical translation of either object or sensor is required; instead, a digital micromirror array is used for scanning the surface. It results in a higher processing rate, better measuring reproducibility, and easy adaptation of the method to specifics of the fabrication technology or object under test. Third, recording a full fringe for a particular pair of object's pixels is done within a single frame of a CCD camera. Also, multiple fringes for the whole line of object pixels can be captur ed at once. Then only 1-D scan is required to recover the depth profile of a 2-D object area. The experimental setup has been constructed to verify major principles of the method and measurement of test samples have been realized and compared to alternative measuring methods

This paper describes charging effects on spatial light modulators (SLM). These light modulators consist of up to one million mirrors that can be addressed individually and are operated at a frame rate of up to 2 kHz. They are used for DUV mask writing where they have to meet very high requirements with respect to accuracy. In order to be usable in a mask-writing tool, the chips have to be able to work under DUV light and maintain their performance with high accuracy over a long time. Charging effects are a problem frequently encountered with MEMS, especially when they are operated in an analog mode. In this paper, the issue of charging effects in SLMs used for microlithography, their causes and methods of their reduction or elimination, by means of addressing methods as well as technological changes, will be discussed. The first method deals with the way charges can accumulate within the actuator, it is a simple method that requires no technological changes but cannot always be implemented. The second involves the removal of the materials within the actuator where charges can accumulate