Nxp Usa, Inc.

Freescale Semiconductor,inc.

Srivatsa G Kundalgurki

Ruben B Montez

James McHugh

Gary Pfeffer

Scott Dye

One embodiment of making a diode includes forming a first electrode to which an electric field is applied; forming a second electrode to which the electric field is applied; and forming a vapor gap region between the first electrode and the second electrode. A total capacitance measured between the first electrode and the second electrode varies based on presence of a polar vapor species on at least a portion of an electrode surface of at least one of the first electrode and the second electrode.

Systems and methods for detecting change in species in an environment

A method of making a microelectromechanical systems (MEMS) device includes etching away a sacrificial material layer to release a mechanical element of the MEMS device. The MEMS device is formed at least partially on the sacrificial material layer, and the etching leaves a residue in proximity to the mechanical element. The residue is exposed to an anhydrous solution to remove the residue. The residue may be an ammonium fluorosilicate-based residue, and the anhydrous solution may include acetic acid, isopropyl alcohol, acetone, or any anhydrous solution that can effectively dissolve the ammonium fluorosilicate-based residue.

Etch release residue removal using anhydrous solution

The present disclosure provides embodiments for diodes, devices, and methods for polar vapor sensing. One embodiment of a diode includes a first electrode to which an electric field is applied; a second electrode to which the electric field is applied; and a vapor gap region between the first electrode and the second electrode. A total capacitance measured between the first electrode and the second electrode varies based on presence of a polar vapor species on at least a portion of an electrode surface of at least one of the first electrode and the second electrode.

A method for determining the concentration of an analyte is provided. The method comprises: applying an alternating voltage to a first electrode and a second electrode of a sensor in the presence of the analyte; measuring a first capacitance of the sensor in presence of the analyte; irradiating the analyte for a predetermined time period at a discrete frequency within a predetermined frequency range; measuring a second capacitance of the sensor at an end of the predetermined time period; determining a difference between the first and second capacitances; and determining the concentration of the analyte based on the difference. Also, the method includes determining a composition of an analyte. The discrete frequency is associated with the difference to determine a frequency response. The frequency response is used to determine the composition of the analyte.

A diode for detecting the presence of radiation includes a P region, an N region, an intrinsic region located between the P region and the N region, and a layer of nanoclusters located adjacent to the intrinsic region.

PIN diode with nanoclusters

Etch stabilizing ions () are introduced, e.g., by ion implantation (), into a portion () of a substrate () underlying an etch window () in a masking layer () covering the substrate (), where a trench () is desired to be formed. When the portion () of the substrate () containing the etch stabilizing ions () is etched to form the trench (), the etch stabilizing ions () are progressively released at the etch interface (') as etching proceeds, substantially preventing gas micro-bubbles or other reaction products at the etch interface (&#x2032;) from disrupting etching. Using this method (), products containing trenches () are much more easily formed and such trenches () have much smoother interior surface ().

Etching trenches in a substrate

MEMS devices () using etched cavities () are desirably formed using multiple etching steps. Preliminary cavities () formed by locally anisotropic etching to nearly the final depth have irregular () sidewalls () and steep and/or inconsistent sidewall () to bottom () intersection angles (). This leads to less than desired cavity diaphragm () burst strengths. Final cavities () with smooth sidewalls (), smaller and consistent sidewall () to bottom () intersection angles (), and having more than doubled cavity diaphragm () burst strengths are obtained by treating the preliminary cavities () with TMAH etchant, preferably relatively dilute TMAH etchant. In a preferred embodiment, a cleaning step is performed between the etching step and the TMAH treatment step to remove any anisotropic etching by-products present on the preliminary cavities' () initial sidewalls (). The multi-step cavity etching procedure is especially useful for forming robust MEMS pressure sensors, but is applicable to any type of MEMS device.

Growing community of inventors

Austin, TX, United States of America

Srivatsa G Kundalgurki