M. G. Buehler

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In this effort we used electrical impedance spectroscopy and a four-probe apparatus, the electrical properties cup (EPC), to measure the properties of various lunar and martian soil simulants. The impedance values are characterized by a resistance-capacitor network that is used to determine the soil conductivity and dielectric constant. In this effort we(More)
An analysis was developed for the influence of a finite drain-source voltage, V<inf>DS</inf>, on dopant profiles derived from the dc MOSFET profile method. It indicates that the measured profile of uniformly doped material falls below the true profile near the surface. The effect occurs because the edge of the depletion region in the silicon is not parallel(More)
A new test structure was developed for evaluating the line spacing between conductors on the same layer by using an electrical measurement technique. This compact structure can also be used to measure the sheet resistance, linewidth, and line pitch of the conducting layer. Using an integrated-circuit fabrication process, this structure was fabricated in(More)
This paper describes results obtained from the E-Tongue 3 apparatus used to characterize residual contaminates in water. This apparatus is intended for use in water quality measurements for the ISS (International Space Station). The apparatus contains nine planar electrochemical cells and a conductivity sensor. Detection of contaminate ions in solution uses(More)
A small planar four-probe test structure for measuring the bulk or collector resistivity of silicon wafers was designed and fabricated with a bipolar transistor process. Analogous to a mechanical square array four-point probe, the planar four-probe structure consists of a large-area base diffusion which is broken at four points through which contact is made(More)
A miniature four-point probe instrument has been developed and applied to the characterization of the moisture content of the Martian soil simulants using fine and coarse silica sand and Moses Lake basalt. The results indicate that the soil resistivity varies over four orders of magnitude as the moisture content varied from 0.1% to over 10%. In addition it(More)
The New Millennium Program (NMP) has been validating new flight technology for eight years. Recently, a field study of how the NMP selected technology for flight validation was performed. One result of the study is that the NMP employed an authority-activity model in making its selections. This explanatory model showed how the NMP blended three different(More)
Because of the recently discovered importance of protons to the upset of spaceborne electronics, a custom 4-kB SRAM (static random-access memory) chip was tested with protons. The SRAM was developed to determine the single-event-upset hardness of CMOS latches using alpha particle measurements, by adjusting an offset voltage that reduces the charge required(More)
A miniature electronic nose (ENose) has been designed and built at the Jet Propulsion Laboratory (JPL), Pasadena, CA, and was designed to detect, identify, and quantify ten common contaminants and relative humidity changes. The sensing array includes 32 sensing films made from polymer carbon-black composites. Event identification and quantification were(More)
A fault chip was designed and fabricated on a 2- mu m CMOS wafer-scale integration (WSI) process with greater than 90% wafer coverage. The chip consists of pinhole array capacitors, serpentine resistors, and comb resistors. These structures are tailored to simulate the basic cell in the WSI circuit. Defect cluster analysis, using the negative binomial(More)