Annealing induced interdiffusion and crystallization in sputtered amorphous Si/Ge multilayers

1997 ◽  
Vol 12 (9) ◽  
pp. 2255-2261 ◽  
Author(s):  
Zs. Czigány ◽  
G. Radnóczi ◽  
K. Järrendahl ◽  
J-E. Sundgren
Keyword(s):  
Crystallization Temperature ◽  
Diffusion Constant ◽  
Amorphous State ◽  
Diffraction Measurement ◽  
Individual Layer ◽  
Cross Sectional ◽  
Short Period ◽  
Amorphous Si ◽  
Si Content ◽  
20 Nm

The intermixing and crystallization of amorphous Si/Ge multilayers (with individual layer thickness between 1.5 and 20 nm) and SiGe alloys produced by dc magnetron sputtering have been studied by cross-sectional transmission electron microscopy and x-ray diffraction. Measurement of the crystallization temperature as a function of the Si content showed that multilayers and alloys with equal composition crystallized at the same temperature. This implies that intermixing precedes crystallization in the multilayers. Close to the crystallization temperature, formation of Kirkendall voids was observed in the short-period Si/Ge multilayers. These voids were found at positions corresponding to the original Si layers, indicating that Si diffuses faster in amorphous Ge than Ge in amorphous Si. The Ge layers in short-period Si/Ge multilayers retained their amorphous state to much higher temperatures than thick amorphous Ge layers. This is shown to be due to inhibition of nucleation by the presence of the layer interfaces. A lower estimate for the Si diffusion constant in crystalline Ge is also determined.

Electrical Resistance Change with Crystallization in Si-Te Amorphous Thin Films

2010 ◽  
Vol 1251 ◽  
Author(s):  
Yuta Saito ◽  
Yuji Sutou ◽  
Junichi Koike
Keyword(s):  
Crystallization Temperature ◽  
Electrical Resistance ◽  
High Resistivity ◽  
Resistance Change ◽  
Amorphous Thin Films ◽  
Resistance Increase ◽  
Stage Crystallization ◽  
Amorphous Si ◽  
Si Content ◽  
Electrical Resistance Change

AbstractThe electrical resistance change of amorphous SixTe100-x (x: 10-23) films during heating was investigated by a two-point probe method. The SixTe100-x films showed two-stage crystallization processes. The film was firstly crystallized to Te and subsequently crystallized to Si2Te3 with an electrical resistance drop. The first crystallization temperature Tx1st slightly increased with increasing Si content, while the second crystallization temperature Tx2nd was independent on the composition and was a constant temperature of 310 °C. In all films, the electrical resistance once increased in the temperature range from 250 to 295 °C before the crystallization of the Si2Te3. This temporal resistance increase could be explained by considering a formation of high-resistivity Si-rich amorphous phase.

Ultramicrotomy as a Technique for Materials Specimen Preparation

1990 ◽  
Vol 48 (2) ◽  
pp. 428-429
Author(s):  
S.R. Glanvill
Keyword(s):  
Materials Science ◽  
Structural Information ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Surfaces And Interfaces ◽  
Beam Analysis ◽  
Flat Embedding ◽  
20 Nm ◽  
Sectional Analysis

This paper summarizes the application of ultramicrotomy as a specimen preparation technique for some of the Materials Science applications encountered over the past two years. Specimens 20 nm thick by hundreds of μm lateral dimension are readily prepared for electron beam analysis. Materials examined include metals, plastics, ceramics, superconductors, glassy carbons and semiconductors. We have obtain chemical and structural information from these materials using HRTEM, CBED, EDX and EELS analysis. This technique has enabled cross-sectional analysis of surfaces and interfaces of engineering materials and solid state electronic devices, as well as interdiffusion studies across adjacent layers.Samples are embedded in flat embedding moulds with Epon 812 epoxy resin / Methyl Nadic Anhydride mixture, using DY064 accelerator to promote the reaction. The embedded material is vacuum processed to remove trapped air bubbles, thereby improving the strength and sectioning qualities of the cured block. The resin mixture is cured at 60 °C for a period of 80 hr and left to equilibrate at room temperature.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

scholarly journals Effect of Multiple Reflows on the Interfacial Reactions and Mechanical Properties of an Sn-0.5Cu-Al(Si) Solder and a Cu Substrate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2367
Author(s):  
Junhyuk Son ◽  
Dong-Yurl Yu ◽  
Yun-Chan Kim ◽  
Shin-Il Kim ◽  
Min-Su Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Heat ◽  
Interfacial Reactions ◽  
Future Application ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Automotive Electronic ◽  
Transmission Electron ◽  
Si Content ◽  
Lead Free Solders

In this study, the interfacial reactions and mechanical properties of solder joints after multiple reflows were observed to evaluate the applicability of the developed materials for high-temperature soldering for automotive electronic components. The microstructural changes and mechanical properties of Sn-Cu solders regarding Al(Si) addition and the number of reflows were investigated to determine their reliability under high heat and strong vibrations. Using differential scanning calorimetry, the melting points were measured to be approximately 227, 230, and 231 °C for the SC07 solder, SC-0.01Al(Si), and SC-0.03Al(Si), respectively. The cross-sectional analysis results showed that the total intermetallic compounds (IMCs) of the SC-0.03Al(Si) solder grew the least after the as-reflow, as well as after 10 reflows. Electron probe microanalysis and transmission electron microscopy revealed that the Al-Cu and Cu-Al-Sn IMCs were present inside the solders, and their amounts increased with increasing Al(Si) content. In addition, the Cu6Sn5 IMCs inside the solder became more finely distributed with increasing Al(Si) content. The Sn-0.5Cu-0.03Al(Si) solder exhibited the highest shear strength at the beginning and after 10 reflows, and ductile fracturing was observed in all three solders. This study will facilitate the future application of lead-free solders, such as an Sn-Cu-Al(Si) solder, in automotive electrical components.

Enhanced crystallization and phase transformation of amorphous silicon nitride under high pressure

2001 ◽  
Vol 16 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Ya-Li Li ◽  
Yong Liang ◽  
Fen Zheng ◽  
Xian-Feng Ma ◽  
Suo-Jing Cui ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Crystallization Temperature ◽  
Amorphous Materials ◽  
Normal Pressure ◽  
Nucleation And Growth ◽  
Amorphous Silicon Nitride ◽  
Amorphous Si

The crystallization and phase transformation of amorphous Si3N4 ceramics under high pressure (1.0–5.0 GPa) between 800 and 1700 °C were investigated. A greatly enhanced crystallization and α–β transformation of the amorphous Si3N4 ceramics were evident under the high pressure, as characterized by that, at 5.0 GPa, the amorphous Si3N4 began to crystallize at a temperature as low as 1000 °C (to transform to a modification). The subsequent a–b transformation occurred completed between 1350 and 1420 °C after only 20 min of pressing at 5.0 GPa. In contrast, under 0.1 MPa N2, the identical amorphous materials were stable up to 1400 °C without detectable crystallization, and only a small amount of a phase was detected at 1500 °C. The crystallization temperature and the a–b transformation temperatures are reduced by 200–350 °C compared to that at normal pressure. The enhanced phase transformations of the amorphous Si3N4 were discussed on the basis of thermodynamic and kinetic consideration of the effects of pressure on nucleation and growth.

A semi-automated measurement of muscle fiber size using the Imaris software

2021 ◽  
Author(s):  
Jennifer E. Gilda ◽  
Joon-Hyuk Ko ◽  
Aviv-Yvonne Elfassy ◽  
Nadav Tropp ◽  
Anna Parnis ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Muscle Fiber ◽  
Cross Sections ◽  
Statistical Tests ◽  
Muscle Fibers ◽  
Fluorescent Labeling ◽  
Cross Sectional ◽  
Short Period ◽  
Fiber Size ◽  
Specific Protease

The size and shape of skeletal muscle fibers are affected by various physiological and pathological conditions, such as muscle atrophy, hypertrophy, regeneration, and dystrophies. Hence, muscle fiber cross-sectional area (CSA) is an important determinant of muscle health and plasticity. We adapted the Imaris software to automatically segment muscle fibers based on fluorescent labeling of the plasma membrane, and measure muscle fiber CSA. Analysis of muscle cross sections by the Imaris semi-automated and manual approaches demonstrated a similar decrease in CSA of atrophying muscles from fasted mice compared with fed controls. In addition, we previously demonstrated that downregulation of the Ca2+-specific protease calpain-1 attenuates muscle atrophy. Accordingly, both the Imaris semi-automated and manual approaches showed a similar increase in CSA of fibers expressing calpain-1 shRNA compared with adjacent non-transfected fibers in the same muscle cross section. Although both approaches seem valid for measurements of muscle fiber size, the manual marking method is less preferable because it is highly time-consuming, subjective, and limits the number of cells that can be analyzed. The Imaris semi-automated approach is user-friendly, requires little training or optimization, and can be used to efficiently and accurately mark thousands of fibers in a short period of time. As a novel addition to the commonly used statistics, we also describe statistical tests that quantify the strength of an effect on fiber size, enabling detection of significant differences between skewed distributions that would otherwise not be detected using typical methods.

A Comparative Study between Conventional and Modified Leishman Stain

2021 ◽  
Vol 8 (2) ◽  
pp. 5-12
Author(s):  
Rizwana Abdul Hye ◽  
Bindiya Gisuthan ◽  
Indira Kariveettil
Keyword(s):  
Conventional Method ◽  
Peripheral Blood ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Health Care Centre ◽  
Cross Sectional ◽  
Modified Method ◽  
Present Cross Sectional Study ◽  
Short Period

Introduction: Leishman stain has been used as the stain of choice for peripheral blood films since many decades .But it has a disadvantage of consuming 15 minutes for the procedure alone thereby increasing the turn around time of peripheral smear reporting. In this study modified Leishman stain was made by adding phenol to conventional Leishman to reduce the staining time to 3 minutes without interfering with the quality of stain. Aim: To study the quality of modified Leishman stain in comparison with conventional preparation on peripheral blood smears. Materials and Methods: The present cross-sectional study was carried out in Central Haematology laboratory of a tertiary health care centre in Southern India. A pilot study was done to determine the ideal ratio of phenol to Leishman powder in preparing modified stain without compromising the staining quality. After obtaining consent, the blood sample was collected in anticoagulated vials. Sample size was calculated to be 85.Two thin wedge smears were prepared from each sample and one was stained with conventional Leishman stain and other with modified Leishman stain. The staining characteristics were assessed and scored by an experienced pathologist in terms of 6 parameters- RBC pattern, nuclear pattern, neutrophil granules, eosinophil granules, platelets and background staining. The grades were 1, 2, 3 & 4 (poor, satisfied, good and excellent). Smears each with grades 2, 3 and 4 were selected for study. The results were analysed by Statistical Package for the Social Sciences (SPSS) software version 16.0. Result: The mean value for the staining quality using conventional method was 4.73 and for modified method was 5.39, and the total score possible is 6. Photomicrograph showed excellent results with modified Leishman stain. Thus from these values we can interpret that modified method gave much more acceptable results than that of conventional method. Conclusion: Unlike the conventional method which requires a total of 15 minutes, to complete the staining process, modified Leishman staining techniques takes only 3 minutes. Blood films can be stained within a short period of time thus aiding in rapid diagnosis and treatment of patients. Keywords: Leishman stain, Modified Leishman stain, Phenol.

Abstract P137: Association Of Equol Producing Capacity With Aortic Calcification In Middle-aged Japanese Men

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Xiao Zhang ◽  
Akira Fujiyoshi ◽  
Aya Kadota ◽  
Vasudha Ahuja ◽  
Abhishek Vishnu ◽  
...  
Keyword(s):  
Serum Levels ◽  
Population Based ◽  
Aortic Calcification ◽  
Inverse Association ◽  
Middle Aged ◽  
Cross Sectional ◽  
Japanese Men ◽  
The Us ◽  
Multivariable Analyses ◽  
20 Nm

Background: Soy isoflavones (ISFs) are regularly consumed in Japan and other Asian countries where some studies showed a significant inverse association of ISFs intake with incident coronary heart disease (CHD). However, a US randomized clinical trial did not find ISFs as anti-atherogenic. This discrepancy may be due to the higher capacity of people in Japan than in the US to produce equol, a metabolite of ISF by the gut microbiome. Equol may have greater anti-atherogenic properties than ISFs. It is unknown whether equol producers (EP), people who produce equol after consuming ISF, have lower aortic calcification (AC), a biomarker of atherosclerosis, as compared to non-EP. Aim: To determine the association between equol producing status and AC in Japanese men. Method: This cross-sectional, population-based study included 302 Japanese men aged 40-49, free of CHD. EP was defined as participants with serum levels of equol ≥20 nM. AC was measured in the entire aorta and quantified by the Agatston method. The presence of AC was defined as AC score ≥10. We analyzed the association between equol producing status and AC using the Tobit and the logistic regressions. Result: We observed 125 participants as EP. In multivariable analyses, EP had non-significantly lower AC score by 147 (95% confidence interval (CI): -386, 92) units and an odds ratio of 0.71 (95% CI: 0.40, 1.26) for the AC presence as compared to non-EP. As significant interaction of equol producing status with age was present, we stratified the analyses by the median age. In men aged 45-49 years, EP had non-significantly lower AC score by 246 units and a non-significant 0.62 times the odds of AC presence as compared to non-EP; the corresponding values in men aged 40-44 were 12 units and 0.91 times (Table). Such an association was not observed with serum ISFs (data not shown). Conclusion: Japanese middle-aged men who were EP had non-significantly lower AC than non-EP and such association was stronger in men aged 45-49 than 40-44 years. Further study with much larger sample size is warranted.

scholarly journals High Performance GAA SNWT with a Triangular Cross Section: Simulation and Experiments

2018 ◽  
Vol 8 (9) ◽  
pp. 1553 ◽  
Author(s):  
Ming Li ◽  
Gong Chen ◽  
Ru Huang
Keyword(s):  
Cross Section ◽  
High Performance ◽  
Silicon Nanowire ◽  
Wet Etching ◽  
Excellent Performance ◽  
Cross Sectional ◽  
Triangular Cross Section ◽  
Tcad Simulation ◽  
Equivalent Distance ◽  
20 Nm

In this paper, we present a gate-all-around silicon nanowire transistor (GAA SNWT) with a triangular cross section by simulation and experiments. Through the TCAD simulation, it was found that with the same nanowire width, the triangular cross-sectional SNWT was superior to the circular or quadrate one in terms of the subthreshold swing, on/off ratio, and SCE immunity, which resulted from the smallest equivalent distance from the nanowire center to the surface in triangular SNWTs. Following this, we fabricated triangular cross-sectional GAA SNWTs with a nanowire width down to 20 nm by TMAH wet etching. This process featured its self-stopped etching behavior on a silicon (1 1 1) crystal plane, which made the triangular cross section smooth and controllable. The fabricated triangular SNWT showed an excellent performance with a large Ion/Ioff ratio (~107), low SS (85 mV/dec), and preferable DIBL (63 mV/V). Finally, the surface roughness mobility of the fabricated device at a low temperature was also extracted to confirm the benefit of a stable cross section.

scholarly journals Development of Dynamic Capabilities for Automotive Industry Performance under Disruptive Innovation

2020 ◽  
Vol 6 (4) ◽  
pp. 97
Author(s):  
Atichat Rotjanakorn ◽  
Pornrat Sadangharn ◽  
Khahan Na-Nan
Keyword(s):  
Firm Performance ◽  
Dynamic Capabilities ◽  
Dynamic Environment ◽  
Past Research ◽  
Disruptive Innovation ◽  
Dynamic Capability ◽  
Competitive Advantages ◽  
Cross Sectional ◽  
Innovative Firm ◽  
Short Period

Dynamic capabilities are creating dramatic change for the industry around the world. Resource-Based View (RBV) theory and Operational capability theory are the basic capabilities of an organization under a normal changing environment. This creates a competitive advantage and organizational success in a relatively short period of time, in which the dynamic environment is not sufficient to cope with this change. Dynamic capability is a concept for managing change under this dynamic environment. Past research supports a direct positive relationship between dynamic capability and firm performance but it did not focus on the mediator variables. This research emphasizes the influences of competitive advantages and innovation capabilities as mediators of dynamic capabilities and firm performance were investigated. A cross-sectional design study was utilised and questionnaires were submitted to 326 firms to test the proposed relationships. IBM SPSS Statistics Base 26, IBM SPSS AMOS 21, and PROCESS macro 3.6 were used for statistical analysis. Results revealed that competitive advantages and innovation capabilities were partially mediated by dynamic capabilities and firm performance. Findings contribute to the literature on empowering leadership and innovative firm performance by highlighting that competitive advantages and innovation capabilities act as mediators to improve dynamic capabilities and enhance innovative firm performance.

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