Heinz Kück

A miniaturized magnetic-field sensor system consisting of a planar fluxgate sensor and a CMOS readout circuitry

Abstract We report on a miniaturized magnetic-field sensor system consisting of a fluxgate sensor fabricated in CMOS-compatible planar technology and a CMOS-ASIC for sensor supply, readout and signal processing using the second-harmonic principle with a feedback loop for zero-field operation. The system exhibits a sensitivity of 9.2±0.1 mV μT−1 for a magnetic field range of ±90 μT and a temperature range of 0 to 70 °C. The 3 dB bandwith is 300 Hz and a noise value of 30 nT Hz −1 2 has been estimated. Using 5 V supply voltage, the power consumption of the system is measured to be 160 mW.

Refractive-index measurements using an integrated Mach-Zehnder interferometer

Abstract In this paper a refractometer system with an integrated optical sensor is presented. The sensitive element is a single or multichannel Mach-Zehnder interferometer (MZI) fabricated on silicon using waveguides made from SiO2 and SiON. The refractometer allows for real-time monitoring of refractive indices of gases and liquids in an index range between 1 and 1.49 using the silicon MZI as a low-cost disposable part.

A thermoelectric infrared radiation sensor with monolithically integrated amplifier stage and temperature sensor

Abstract We report on a monolithic integrated infrared sensor system consisting of a thermopile, a sensor measuring the chip temperature and an amplifier stage fabricated in a CMOS process on SIMOX (separation by implanted oxygen) wafers. A responsivity of 209 V W−1 and a normalized detectivity D ∗ of 1.3 × 108 cm Hz 1 2 W−1 are found for thermopiles with single-crystalline p-Si/n-polysilicon thermocouples on silicon oxide/silicon nitride membranes. A first analysis of the thermal influence of the power consumed by the circuitry on the thermopile voltage indicates that the sensor performance is not deteriorated by the integrated electronic circuitry.

Deformable micromirror devices as phase-modulating high-resolution light valves

Abstract We report on two different technologies for deformable micromirror devices as phase-modulating light valves for high-resolution optical applications. Both technologies are compatible with a 30 V CMOS technology for active matrix addressing. We have developed and fabricated a 512 × 464 pixel light valve with CMOS addressing and viscoelastic layer deformable mirrors on top. The performance of the light valve has been demonstrated by an application for fast submicron laser direct writing. Furthermore, we report promising results on cantilever-type deformable mirrors to be integrated with the CMOS active matrix.

New system for fast submicron optical direct writing

Abstract We report on a new system for submicron lithography by fast laser direct writing, where a programmable phase modulating spatial light modulator (SLM) is imaged onto the water using flash on the fly exposure with an excimer laser light source. A SLM with 512×464 pixels has been developed and fabricated using a CMOS active matrix and a reflective, deformable viscoelastic layer on top. Using this light modulator for image generation a demonstrator exposure tool for 0.6μm minimum feature size has been set up and tested including all the components necessary for the exposure of a complete lithographic layer from CAD layout data. The demonstrator is shown to give good quality 0.6μm photoresist pattern at a throughput of roughly one 4″-wafer per hour. Based on the demonstrator results we are designing and setting up a prototype of a production tool with an increased throughput of up to nine 6″-wafers per hour including an automatic alignment system and an automatic wafer handler.

A fully CMOS-compatible infrared sensor fabricated on SIMOX substrates

Abstract We report on the use of SIMOX substrates for fabrication of IR radiation thermopiles by CMOS technology. SIMOX technology enables the fabrication of single-crystal leads on thin silicon or silicon oxide membranes. Two p-type silicon/aluminium thermopiles on different membranes are presented. A thermopile with a 4 μm thick, epitaxially grown silicon membrane has a responsivity of 18 V/W and a time constant of 3 ms. Using a 2.5 μm thick silicon oxide membrane, a responsivity of 150 V/W and a time constant of 25 ms are achieved. In addition, the fabrication and properties of an IR absorber made in CMOS technology are presented.

CMOS-compatible integration of thin ferromagnetic films

Abstract We report on a new process technology for integration of ferromagnetic layers up to about 500 nm thick in a commercial 1.5 μm double-metal CMOS process allowing enhanced process temperatures up to 400 °C. The nickel-iron structure is placed between two metallization levels, separated by SiO 2 interlayer dielectric films. Pattern definition is done with an aluminium mask, which can withstand the high temperature stress during nickel-iron deposition. We have fabricated nickel-iron structures with widths down to 4 μm. The three-metal-level process sequence presented here enables three-dimensional integrated coils with a ferromagnetic core to be fabricated.

Deformable Micromirror Devices As Phase Modulating High Resolution Light Valves

We report on two different technologies for deformable micromirror devices as phase modulating light valves for high resolution optical applications. Both technologies are compatible with a 30V CMOS technology for active matrix addressing. We have developed and fabricated a 512 x 464 pixel light valve with CMOS addressing and viscoclastic layer deformable mirrors on top. The performance of the light valve has been demonstrated by an application for fast submicron laser direct writing. Furthermore we report on promising results on cantilever-type deformable mirrors to be integrated with the CMOS active matrix.

New alpha radiation detection systems for environmental surveys

We report on the development of low-cost alpha-particle sensor systems for radon and radon daughter monitoring and dosimetry (Ealpha= 5.5–7.9 MeV) and on the first application for environmental surveys. It is known that commercial dRAM cells are sensitive to alpha particles, but their efficiency is at most 20%, resulting in an unstable operating range (Ucc<4 V). Furthermore it is known that p-n diodes and phototransistors are also very sensitive to alpha particles. Our first development in the field of alpha-radiation detection systems has been based on our experience in the field of high-density dRAMs by improving the collecting efficiency for electron-hole pairs generated in the substrate by the incidence of alpha particles. Using the experience of the MEGARAD-microsystem, we have developed an alpha-particle spectroscopic sensor array with special PMOS transistors in a floating n-well as sensor cells. 1024 sensor cells, the preamplifiers, the analog memories, a fast four-bit parallcal*|A/D converter and the address-coding system are integrated on a single chip. The chip area is 56 mm2 and the effective sensor area is 40 mm2. The energy resolution for 5 MeV alpha particles is better than 300 keV. The dead time is smaller than 10% for up to 106 alpha particles per second and per square centimetre. The systems are tested in several radiation fields (neutron, proton, alpha, beta and gamma radiation). The efficiency of the alpha-radiation detection systems in radon-monitoring systems is proved in various applications. The use of low-cost alpha-particle detection systems in radon-monitoring systems is a big advance for environmental surveys.