Experiments on the Release of CMOS-Micromachined Metal Layers

We present experimental results on the release of MEMS devices manufactured using the standard CMOS interconnection metal layers as structural elements and the insulating silicon dioxide as sacrificial layers. Experiments compare the release results of four different etching agents in a CMOS technology (hydrofluoric acid, ammonium fluoride, a mixture of acetic acid and ammonium fluoride, and hydrogen fluoride), describe various phenomena found during the etching process, and show the release results of multilayer structures.

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HETEROGENEOUS CATALYTIC CONVERSIONS OF ACETYLENE

CHEMISTRY AND CHEMICAL ENGINEERING ◽

10.51348/gttb5269 ◽

2021 ◽

pp. 45-57

Keyword(s):

Acetic Acid ◽

Water Vapor ◽

Hydrofluoric Acid ◽

Heterogeneous Catalysts ◽

Ammonium Fluoride ◽

Catalyst Carrier ◽

Heterogeneous Catalytic ◽

Pyridine Bases ◽

Cadmium Zinc ◽

Selection Of

The reactions of interaction of acetylene with water vapor, acetic acid and ammonia in the presence of heterogeneous catalysts have investigated. Depending on the nature of the starting components used, acetaldehyde and acetone, vinyl acetate, pyridine bases and pyrrole synthesized. Heterogeneous catalysts selected for each studied reaction based on some scientific prerequisites for the selection of catalysts. Active catalysts for the investigated reactions were determined, which contain compounds of cadmium, zinc, bismuth, chromium, iron and copper, in general, d-group metals. γ-Al2O3, bentonite and kaolin used as a catalyst carrier. Hydrofluoric acid, acetic acid, ammonium fluoride and others used for peptization. Some hypothetical mechanisms for the formation of target products for each reaction have proposed.

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Molecular Dynamics Simulation of Silicon Dioxide Etching by Hydrogen Fluoride Using the Reactive Force Field

ACS Omega ◽

10.1021/acsomega.1c01824 ◽

2021 ◽

Author(s):

Dong Hyun Kim ◽

Seung Jae Kwak ◽

Jae Hun Jeong ◽

Suyoung Yoo ◽

Sang Ki Nam ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Silicon Dioxide ◽

Force Field ◽

Hydrogen Fluoride ◽

Dynamics Simulation ◽

Reactive Force ◽

Reactive Force Field

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A Tunable-Gain Transimpedance Amplifier for CMOS-MEMS Resonators Characterization

Micromachines ◽

10.3390/mi12010082 ◽

2021 ◽

Vol 12 (1) ◽

pp. 82

Author(s):

Rafel Perelló-Roig ◽

Jaume Verd ◽

Sebastià Bota ◽

Jaume Segura

Keyword(s):

Cmos Technology ◽

Open Loop ◽

Transimpedance Amplifier ◽

Mems Devices ◽

Monolithically Integrated ◽

Mems Resonators ◽

Electromechanical Performance ◽

Cmos Mems ◽

Promising Solution ◽

On Chip

CMOS-MEMS resonators have become a promising solution thanks to their miniaturization and on-chip integration capabilities. However, using a CMOS technology to fabricate microelectromechanical system (MEMS) devices limits the electromechanical performance otherwise achieved by specific technologies, requiring a challenging readout circuitry. This paper presents a transimpedance amplifier (TIA) fabricated using a commercial 0.35-µm CMOS technology specifically oriented to drive and sense monolithically integrated CMOS-MEMS resonators up to 50 MHz with a tunable transimpedance gain ranging from 112 dB to 121 dB. The output voltage noise is as low as 225 nV/Hz1/2—input-referred current noise of 192 fA/Hz1/2—at 10 MHz, and the power consumption is kept below 1-mW. In addition, the TIA amplifier exhibits an open-loop gain independent of the parasitic input capacitance—mostly associated with the MEMS layout—representing an advantage in MEMS testing compared to other alternatives such as Pierce oscillator schemes. The work presented includes the characterization of three types of MEMS resonators that have been fabricated and experimentally characterized both in open-loop and self-sustained configurations using the integrated TIA amplifier. The experimental characterization includes an accurate extraction of the electromechanical parameters for the three fabricated structures that enables an accurate MEMS-CMOS circuitry co-design.

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Fast-Hardening Foam: Fire and Explosion Prevention at Facilities with Hazardous Chemicals

Journal of Materials Science Research ◽

10.5539/jmsr.v6n4p56 ◽

2017 ◽

Vol 6 (4) ◽

pp. 56

Author(s):

Gennady N. Kuprin ◽

Denis S. Kuprin

Keyword(s):

Acetic Acid ◽

Hydrogen Chloride ◽

Hydrogen Fluoride ◽

Diesel Fuel ◽

High Probability ◽

Hydrogen Bromide ◽

Screening Method ◽

Hazardous Chemicals ◽

Experimental Apparatus ◽

Fire And Explosion

Analysis of the terroristic attacks in Siria, Afghanistan and other countries has shown high probability of the hazardous chemicals application by the terroristic groups. In the article the most catastrophic accidents which were connected with hazardous chemicals are described.That is why research and developments in the sphere of protection from hazardous chemicals are still actual.This article is dedicated to the new screening method of the spilled hazardous chemicals surface on the example of protection of the factories with these substances. Methodology, experimental apparatus, protective fast-hardening foam features, names of hazardous chemicals are shown.Test were made for such chemicals as: acetic acid, acetone, ammonia, bromine, chlorbenzene, chloroform, hydrogen bromide, hydrogen chloride, hexane, hydrazine, diesel fuel, dichlorethane, kerosene, toluene, phenol, hydrogen fluoride. Fantastic results were achieved in terms of isolating capability of the fast-hardening foam against evaporations of the pointed substances.

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Étude polarographique du niobium dans les mélanges eau – fluorure d'hydrogène

Canadian Journal of Chemistry ◽

10.1139/v83-463 ◽

1983 ◽

Vol 61 (12) ◽

pp. 2699-2702 ◽

Cited By ~ 2

Author(s):

H. Ménard ◽

R. Beaudoin

Keyword(s):

Hydrogen Fluoride ◽

Hydrofluoric Acid ◽

Water Hydrogen

Solubilization in hydrogen fluoride is required for the analysis of some minerals. A method of analysis directly applicable to water – hydrogen fluoride mixtures was worked out.However, in 50% hydrofluoric acid niobium is soluble as [Formula: see text] complex, which can be reduced with a polarographic electrode at a potential of −0.880 V vs. E.C.S. For concentrations lower than 45% in HF, the niobium complex is hydrated and exists as a non-reducible ion [Formula: see text].

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