Sandia Corporation

The United States of America As Represented by the United States

New Mexico Tech Research Foundation

W Kent Schubert

Michael A Butler

Ronald P Manginell

Randy J Shul

Paul Charles Galambos

Douglas Ray Adkins

Harold L Stalford

Stephen J Martin

Gregory C Frye

Robert C Hughes

Douglas S Ruby

Deidre Hirschfeld

Christi Gober Willison

Larry F Anderson

Paul A Basore

Chad S Watson

Mary-Anne Mitchell

New methods for fabrication of silicon microstructures have been developed. In these methods, an etching delay layer is deposited and patterned so as to provide differential control on the depth of features being etched into a substrate material. Compensation for etching-related structural artifacts can be accomplished by proper use of such an etching delay layer.

Method to control artifacts of microstructural fabrication

A method for tuning a vibratory device including a cantilevered resonator comprising the steps of increasing a voltage Vsupplied to the vibratory device to thereby increase the bandwidth of the vibratory device; and keeping the resonant frequency of the vibratory device at substantially that natural frequency of the cantilevered resonator, wherein the vibratory device comprises: a capacitor including a movable plate and a fixed plate spaced from each other, the movable plate being part of the cantilevered resonator; a voltage source connected to the capacitor for providing voltage Vacross the capacitor to produce an attractive force between movable plate and fixed plate; a circuit connecting the voltage source to the capacitor; and a load resistor in said circuit having a resistance Rsatisfying the following equation:where: &#x3bc; is at least 10; &#x3c9;is the beam constant for the cantilevered resonator; cis the capacitance for the capacitor; and &#x3bb; is the voltage dependent coupling parameter for voltage V.

Multi-tunable microelectromechanical system (MEMS) resonators

New methods for fabrication of silicon microstructures have been developed. In these methods, an etching delay layer is deposited and patterned so as to provide differential control on the depth of features being etched into a substrate material. Structures having features with different depth can be formed thereby in a single etching step.

Method to fabricate multi-level silicon-based microstructures via use of an etching delay layer

A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

Micro acoustic spectrum analyzer

A method is provided for anodically bonding glass and semiconducting material. A glass sample is immersed in a molten salt bath for a fixed period of time to modify the surface of the glass sample via ion exchange. The salt is a lithium salt or a proton source. After the glass sample is removed from the salt bath, the glass sample and semiconducting material are placed onto one another, and are then heated to a temperature of between 100&deg; C. and 500&deg; C. While at this temperature, a potential is applied across the glass and semiconducting material for a fixed period of time to effect anodic bonding together of the glass and semiconducting material.

Method for anodically bonding glass and semiconducting material together

A process for making high-efficiency solar cells. This is accomplished by forming a diffusion junction and a passivating oxide layer in a single high-temperature process step. The invention includes the class of solar cells made using this process, including high-efficiency solar cells made using Czochralski-grown silicon.

Method for fabricating silicon cells

An apparatus and method is provided for separating and analyzing chemical species in an ion mobility spectrometer using a frequency-domain technique wherein the ions generated from the chemical species are selectively transported through an ion flow channel having a moving electrical potential therein. The moving electrical potential allows the ions to be selected according to ion mobility, with certain of the ions being transported to an ion detector and other of the ions being effectively discriminated against. The apparatus and method have applications for sensitive chemical detection and analysis for monitoring of exhaust gases, hazardous waste sites, industrial processes, aerospace systems, non-proliferation, and treaty verification. The apparatus can be formed as a microelectromechanical device (i.e. a micromachine).

Ion mobility spectrometer using frequency-domain separation

An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.

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Albuquerque, NM, United States of America

W Kent Schubert