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In this paper, we present a piston-type spatial light modulator (SLM) as a programmable optical pattern generator for maskless lithography. The SLM is a dual-lever-type actuator with pixel-overlapping springs to achieve low voltage actuation with a small capacitor area. Large arrays of up to ~40000 mirrors with 20-mum pixels and ~17000 mirrors with 30-mum pixels have been fabricated. The arrays have various prewired configurations to alleviate the need to control all the pixels individually. The mirrors have high resonance frequencies for fast response and achieve deflections of lambda/2 (lambda=193 nm for 20-mum pixels and lambda=633 nm for 30-mum pixels) at voltages less than 100 V. The mirrors are fabricated using thin-film processing and chemical mechanical polishing of the reflector layer. Using the SLM in an aerial imaging system, we demonstrate the generation of dark lines, dark areas, linewidth modulation, and subgrid positioning. We also demonstrate compensation of image shifts due to through-focus wafer drift using a double exposure (or phase-compensated exposure) technique [ABSTRACT FROM PUBLISHER]

We report on a tunable optical bandpass filter with precise and independent control of its optical bandwidth and center wavelength. The optical filter is based on a double-pass monochromator configuration and a variable-aperture microelectromechanical systems (MEMS) reflector with two blocking micromirrors that manipulate the optical passband. The MEMS reflector is fabricated on the sidewalls of (110) silicon-on-insulator material by a combination of wet etching and deep reactive ion etching. The 1-dB optical bandwidth is continuously tunable from 3.65 to 6.35 nm by changing the position of the blocking micromirrors with lateral combdrive actuators. The center wavelength can be accurately controlled within a 30-nm spectral range by rotating the diffraction grating and/or changing the center location of the variable aperture with the combdrive actuators. The measured group delay variation across the passband was negligible [ABSTRACT FROM PUBLISHER]

We present a micromechanical grating array that acts as a configurable optical filter for low-cost and compact visible and near-infrared spectrometric sensors. We show how the grating array can be used either as a fast scanning monochromator or as a diffractive filter, and that the expected signal-to-noise ratio is approximately equal for the two modes of measurement. The free spectral range of the filter can be matched to a defined spectral measurement region, so that we can optimize the relationship between spectral resolution and electromechanical complexity. We have numerically studied diffraction efficiency and errors in filter shape. Finally, we fabricated a small configurable grating array and present measurement results that demonstrate electrostatic filter modulation. [ABSTRACT FROM PUBLISHER]

A multi-functional microelectromechanical system (MEMS) tunable optical filter as an amplified spontaneous emission (ASE) rejection filter in an optical communication system is presented. The MEMS tunable filter can tune both the centre wavelength and the passband independently and continuously in C-band. This filter was applied to a 10 Gbit/s system and system-performance improvement by adjusting the amount of ASE noise rejection was observed. [ABSTRACT FROM AUTHOR]