Mechanical Performance of Silicon Diaphragm for Space Application

2004 ◽  
Author(s):  
Yi Zhao ◽  
Biao Li ◽  
Daryl Ludlow ◽  
Xin Zhang
Keyword(s):  
Cryogenic Temperature ◽  
Mechanical Performance ◽  
Fatigue Testing ◽  
Single Crystal Silicon ◽  
Life Time ◽  
Crystal Silicon ◽  
Time Operation ◽  
Micro Pump ◽  
Satellite Applications ◽  
Long Time

In micro satellites, delicate instrumentations are compacted into a limited space. It raises concerns of active cooling and remote cooling. Silicon based micro-pump arrays are employed thanks to manufacturing simplicity, a small cryogen charge, etc., which keeps the instrumentations within a narrow cryogenic temperature range. The mechanical performance of the silicon diaphragm, the key component of the micro-pump, is critical in terms of heat balance calculation and life time evaluation. This paper examines the mechanical performance of the silicon diaphragm under cryogenic temperature for micro satellite applications. In this work, differential pressure was used for the actuation of a single-crystal silicon diaphragm. Diaphragm deflection and stress distribution were achieved using interferometry and micro Raman spectroscopy, respectively. As a result, a higher elastic modulus was associated with the diaphragm under cryogenic temperature, comparing to that under room temperature, indicating a stiffer material. From stress mapping, the edge centers were believed to be the most vulnerable to fracture, which was further validated by analyzing the fracture diaphragm. Moreover, a fatigue testing was conducted for 1.8 million cycles with no damage found, verifying thin film silicon as a viable material for long time operation in a cryogenic environment.

A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays

2014 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee
Keyword(s):  
Reverse Bias ◽  
High Efficiency ◽  
Life Time ◽  
Density Currents ◽  
High Brightness ◽  
Light Emitting ◽  
Wide Viewing Angle ◽  
Time Operation ◽  
Long Time ◽  
History Of

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.

Resonant fatigue testing of single-crystal silicon torsional micromirror

2018 ◽  
Vol 2018 (0) ◽  
pp. J2230304
Author(s):  
Kazutaka OBITANI ◽  
Wenlei ZHANG ◽  
Yoshikazu HIRAI ◽  
Toshiyuki TSUCHIYA ◽  
Osamu TABATA
Keyword(s):  
Single Crystal ◽  
Fatigue Testing ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Torsional Micromirror

Life Time Predictions through X-Ray Defect Analysis of MEMS Devices

2008 ◽  
Vol 584-586 ◽  
pp. 518-522 ◽  
Author(s):  
Antonia Neels ◽  
Philippe Niedermann ◽  
Alex Dommann
Keyword(s):  
Single Crystal Silicon ◽  
Life Time ◽  
Defect Analysis ◽  
Mems Devices ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
Crystal Silicon ◽  
Rocking Curve ◽  
X Ray ◽  
Curve Method

In single crystal silicon (SCSi) MEMS devices, crystalline imperfection is recognized to favor failure. A DRIE etched SCSi structure was built to study the crystal strain profile in dependence of the SCSi deformation by applying a mechanical force. High resolution X-ray diffraction methods such as the rocking curve method and reciprocal space mapping were used to determine the strain as well as the defect concentration in the crystal. The investigations also include the numerical simulation of deformations.

Parallel tensile-mode fatigue testing of single crystal silicon by specimen integrating shear strain gauge

2018 ◽  
Vol 2018 (0) ◽  
pp. J2230303
Author(s):  
Yuki YAMAZAKI ◽  
Kanji YASUDA ◽  
Yoshikazu HIRAI ◽  
Toshiyuki TSUCHIYA ◽  
Osamu TABATA
Keyword(s):  
Single Crystal ◽  
Shear Strain ◽  
Strain Gauge ◽  
Fatigue Testing ◽  
Single Crystal Silicon ◽  
Crystal Silicon

HREM observation of dislocations near room temperature fractures in silicon

1988 ◽  
Vol 46 ◽  
pp. 892-893
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan
Keyword(s):  
Cross Section ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Dislocation Nucleation ◽  
Back Side ◽  
Ion Milling ◽  
Crystal Silicon ◽  
Flat Surfaces ◽  
Induced Fractures ◽  
Vicker’S Microhardness

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.

Analysis of Silicon-On-Insulator Structures Formed By Oxygen Ion Implantation

1985 ◽  
Vol 43 ◽  
pp. 300-301
Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Dose ◽  
Crystal Silicon ◽  
Oxygen Ion ◽  
Oxygen Ion Implantation

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.

Strain measurement by means of bend contour microscopy

1989 ◽  
Vol 47 ◽  
pp. 210-211
Author(s):  
Philip D. Hren
Keyword(s):  
Strain Measurement ◽  
Large Angle ◽  
Single Crystal Silicon ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Silicon Membrane ◽  
Crystal Silicon ◽  
Contour Pattern ◽  
Convergent Beam ◽  
Low Symmetry

The pattern of bend contours which appear in the TEM image of a bent or curled sample indicates the shape into which the specimen is bent. Several authors have characterized the shape of their bent foils by this method, most recently I. Bolotov, as well as G. Möllenstedt and O. Rang in the early 1950’s. However, the samples they considered were viewed at orientations away from a zone axis, or at zone axes of low symmetry, so that dynamical interactions between the bend contours did not occur. Their calculations were thus based on purely geometric arguments. In this paper bend contours are used to measure deflections of a single-crystal silicon membrane at the (111) zone axis, where there are strong dynamical effects. Features in the bend contour pattern are identified and associated with a particular angle of bending of the membrane by reference to large-angle convergent-beam electron diffraction (LACBED) patterns.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

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