New transverse piezoresistance and pinch effect electromechanical transducers: A concept

Abstract When using Inductively Coupled Plasma (ICP) as a machining tool, its processing method based on the principle of chemical etching leads to no contact stress between the tool and the material, thereby generating no mechanical damage. In recent years, this issue has been widely concerned in the field of optical fabrication. However, there are many differences between low power ICP jet and conventional ICP jet, one of which is that the former does not easily form a rotation-symmetric removal function due to its obvious pinch effect. In this research, the electromagnetism principle of the plasma pinch effect was analyzed firstly, and the jet shape under the pinch effect was classified. Then, experimental study was carried out on the plasma jet shape under the pure Ar and mixed gas of CF4-Ar, and the influence law of the reaction gas on the jet propagation shape was analyzed. Finally, the rotational symmetry of the removal function of plasma jet processing was optimized, and the nozzle design criteria based on pinch effect were proposed.

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Design and Calibration of Resistive Stress Sensors on 4H Silicon Carbide

ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2018-8219 ◽

2018 ◽

Cited By ~ 2

Author(s):

Richard C. Jaeger ◽

Jun Chen ◽

Jeffrey C. Suhling ◽

Leonid Fursin

Keyword(s):

Silicon Carbide ◽

Integrated Circuits ◽

Stress Sensitivity ◽

Well Drilling ◽

Deep Well ◽

Stress Sensors ◽

Wide Range ◽

Higher Temperature ◽

Van Der Pauw ◽

Transverse Piezoresistance

Stress sensors have shown potential to provide “health monitoring” of a wide range of issues related to packaging of integrated circuits, and silicon carbide offers the advantage of much higher temperature sensor operation with application in packaged high-voltage, high-power SiC devices as well as both automotive and aerospace systems, geothermal plants, and deep well drilling, to name a few. This paper discusses the theory and uniaxial calibration of resistive stress sensors on 4H silicon carbide (4H-SiC) and provides new theoretical descriptions for four-element resistor rosettes and van der Pauw (VDP) stress sensors. The results delineate the similarities and differences relative to those on (100) silicon: resistors on the silicon face of 4H-SiC respond to only four of the six components of the stress state; a four-element rosette design exists for measuring the in-plane stress components; two stress quantities can be measured in a temperature compensated manner. In contrast to silicon, only one combined coefficient is required for temperature compensated stress measurements. Calibration results from a single VDP device can be used to calculate the basic lateral and transverse piezoresistance coefficients for 4H-SiC material. Experimental results are presented for lateral and transverse piezoresistive coefficients for van der Pauw structures and p- and n-type resistors. The VDP devices exhibit the expected 3.16 times higher stress sensitivity than standard resistor rosettes.

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