Effect of Wheel Additive On Chemo-Mechanical Grinding (CMG) of Single Crystal Si Wafer

2010 ◽  
Vol 447-448 ◽  
pp. 106-110 ◽  
Author(s):  
H. Takahashi ◽  
Y.B. Tian ◽  
Y. Mikami ◽  
J. Shimizu ◽  
Li Bo Zhou ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Single Crystal ◽  
Sodium Carbonate ◽  
Low Cost ◽  
The Other ◽  
Si Substrate ◽  
Mechanical Grinding ◽  
Different Types ◽  
Selection Of ◽  
Si Wafer

Chemo-mechanical grinding (CMG) process is a promising process for large-sized Si substrate fabrication at low cost. However, effect of additive in CMG wheel is not completely understood yet. In this paper, three different CMG wheels were developed, in which one excluded additive and the other two contained two kinds of additive i.e. silicon dioxide and sodium carbonate. Grinding experiments were conducted to explore the influence of exclusion of additive and inclusion of different kinds of additive on CMG performance. The grinding characteristics of the three wheels were also analyzed and discussed to reveal the roles of wheel compositions in CMG process. This work provides some fundamental insights for the selection of different types of additive for optimization of CMG wheel.

Effects of Sodium Carbonate and Ceria Concentration on Chemo-Mechanical Grinding of Single Crystal Si Wafer

2009 ◽  
Vol 76-78 ◽  
pp. 428-433 ◽  
Author(s):  
H. Takahashi ◽  
Y.B. Tian ◽  
J. Sasaki ◽  
Jun Shimizu ◽  
Li Bo Zhou ◽  
...  
Keyword(s):  
Single Crystal ◽  
Sodium Carbonate ◽  
Low Cost ◽  
Wafer Surface ◽  
Si Substrate ◽  
Mechanical Grinding ◽  
Grinding Performance ◽  
Si Wafer

Chemo-mechanical grinding (CMG) process is a promising process for large-sized Si substrate fabrication at low cost. An encountered issue in current CMG process of Silicon (Si) wafers is metallic contaminations on ground Si wafer surface, which is attributed to the existence of sodium carbonate in wheel compounds. In this paper, four different CMG wheels were developed and grinding experiments were conducted to study the effects of exclusion of sodium carbonate and concentration of ceria abrasive on grinding performance. The grinding characteristics of the four wheels were analysized and discussed to reveal the effects of different compositions.

Efficient and Robust Approach for Heartbeat Detection of ECG Signal

2019 ◽  
Vol 29 (08) ◽  
pp. 2050133
Author(s):  
Anas Fouad Ahmed ◽  
Mohammed Abdulmunem Ahmed ◽  
Hussain Mustafa Bierk
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Suggested Method ◽  
The Other ◽  
Ecg Signal ◽  
Excellent Performance ◽  
Robust Approach ◽  
Different Types ◽  
Three Stages ◽  
Electrocardiogram Ecg

This paper introduces an efficient and robust method for heartbeat detection based on the calculated angles between the successive samples of electrocardiogram (ECG) signal. The proposed approach involves three stages: filtering, computing the angles of the signal and thresholding. The suggested method is applied to two different types of ECG databases (QTDB and MIT-BIH). The results were compared with the other algorithms suggested in previous works. The proposed approach outperformed the other algorithms, in spite of its simplicity and their fast calculations. These features make it applicable in real-time ECG diagnostics systems. The suggested method was implemented in real-time using a low cost ECG acquisition system and it shows excellent performance.

Reliability Improvement in Silicon Dioxide

2012 ◽  
Vol 725 ◽  
pp. 231-234
Author(s):  
Masashi Minami ◽  
Yoichi Kamiura
Keyword(s):  
Silicon Dioxide ◽  
The Other ◽  
Si Substrate ◽  
Silicon Oxidation ◽  
Reliability Improvement ◽  
Dry Oxidation ◽  
Characteristic Values

There are two typical methods for silicon oxidation. One is pyrogenic oxidation using oxygen and hydrogen, the other is dry oxidation using oxygen. In this study various properties of these oxidation films were compared. The pyrogenic oxidation in turn could show better characteristic values in the all experiments. Furthermore, once dry oxidation was used even before gate oxidation, we found that dry oxidation made a source of defects generation at surface of the Si substrate.

A Theoretic Study on Cam-Clamping Device

2011 ◽  
Vol 295-297 ◽  
pp. 1536-1539 ◽  
Author(s):  
Yuan Chao Deng
Keyword(s):  
Simple Structure ◽  
Theoretical Study ◽  
Low Cost ◽  
The Self ◽  
Clamping Force ◽  
Locking Mechanism ◽  
Different Types ◽  
Cam Profile ◽  
Clamping Device ◽  
Selection Of

A theoretical study has been made on the cam-clamping device. In this article, we consider specifically the calculations of cam geometry, calculations of clamping force and clamping torque, conditions for self-locking, and conditions for contact strength. Machine fixtures are essential in the process of mechanical manufacturing. There are many different types of fixtures, such as manual jig, pneumatic clamps, hydraulic fixtures, electric fixtures, etc. There are also many ways of clamping, such as incline clamp, screw clamp, eccentric circle clamp, hinge clamp [1], among which the eccentric circle clamp finds wide applications, especially in fast-clamping devices. Although the circular eccentric fixture possesses the advantages of simple structure, convenient manufacturing, and low cost, it suffers the drawbacks of small clamping force, short clamping-surface travel distance, and unreliable self-locking mechanism. The cam-clamping device discussesed in this article involves replaceing the eccentric circle with a cam, as shown in Fig. 1. The cam profile curve can be designed according to any requirements. The advantages of this replacement are obvious, in addition to preserving the advantages of the circular eccentric fixture, the cam-clamping can be designed according to the actual needs of clamping paths and selection of the appropriate cam profile to improve the self-locking.

scholarly journals Organisation of funerary areas and character of burial practices at Pohansko near Břeclav (based on a comparison of the cemetery around the second church and the dispersal burial grounds in the stronghold’s southern suburb)

2019 ◽  
Vol 72 (1-2) ◽  
pp. 46-61
Author(s):  
Renáta Přichystalová
Keyword(s):  
Local Community ◽  
The Other ◽  
Burial Practices ◽  
The North ◽  
Burial Customs ◽  
North Eastern ◽  
Different Types ◽  
Burial Rites ◽  
Burial Grounds ◽  
Selection Of

At the early medieval site Břeclav – Pohansko we can distinguish two different types of funerary areas: church cemeteries with clearly defined locus sacer and dispersed burial grounds in settlements, where the boundary between the living and funerary spaces is not clearly defined. The organisation of the area for funerary activities, the selection of the burial place and the homogeneity of applied burial rites in the above-mentioned two types of funerary areas were different. In order to find out how extensive this difference is, we chose several characteristics of funerary areas and compared them with one another. The key determinants were: the spatial structure of funerary areas, and the orientation and position of individuals buried in grave pits. As an example of a church cemetery we chose the cemetery around the second church in the North-Eastern Suburb of Pohansko. The Southern Suburb of the stronghold yielded data related to funerary areas dispersed in and between settlement structures. The comparison of selected characteristics of burial customs identified in the above-mentioned church cemetery and in dispersed cemeteries demonstrates that burials around churches were most probably organised and planned centrally and that the organisation and supervision of funerary activities might have been in the hands of the clergy. The burials in cemeteries within the settlement structure, on the other hand, were organised in accordance with customs of local community. The organisation and supervision of these funerary areas were most probably in the hands of persons approved and authorised by the community, maybe some significant community member, or the “Council of Elders” or pagan priests.

Intriguing Absorption Band Behavior of IR Reflectance Spectra of Silicon Dioxide on Silicon

1988 ◽  
Vol 42 (4) ◽  
pp. 598-604 ◽  
Author(s):  
James S. Wong ◽  
Yu-Sze Yen
Keyword(s):  
Silicon Dioxide ◽  
Incident Angle ◽  
Polarized Light ◽  
Reflectance Spectra ◽  
Infrared Reflectance ◽  
Si Substrate ◽  
Ir Reflectance ◽  
Spectral Simulations ◽  
Polarization Spectra ◽  
Si Wafer

Infrared reflectance spectra of a thermally grown 30-nm SiO2 film on a Si wafer were measured as a function of incident angle and polarization. Spectra measured with s-polarized light resemble the published extinction coefficient for SiO2. The p-polarized spectra show significant distortions at all incident angles. Bands change in frequency and intensity and can even invert as the incident angle increases beyond the Brewster angle of the Si substrate. Spectral simulations using the classical electromagnetic equations reproduce these distortions.

scholarly journals Comunicación simétrica y asimétrica en los blogs de divulgación jurídica: entre modalidad epistémica y modalidad deóntica

2018 ◽  
pp. 175-191
Author(s):  
Gianluca Pontrandolfo ◽  
Sara Piccioni
Keyword(s):  
Epistemic Modality ◽  
The Other ◽  
Legal Knowledge ◽  
Qualitative And Quantitative ◽  
Situational Contexts ◽  
Legal Texts ◽  
Different Types ◽  
Legal Expert ◽  
Symmetrical Communication ◽  
Selection Of

 This paper aims at investigating some discursive features of blawgs, namely legal blogs in which legal experts disseminate and popularise their expertise. More specifically, it involves a corpus-assisted discourse study of the ways in which situational contexts affect the practices and strategies used to represent, construct and communicate legal knowledge. A comparison is drawn between two corpora representative of two different types of communication: a selection of posts written by legal experts for other experts (symmetrical communication) and posts written by legal experts for laypersons (asymmetrical communication). Combining qualitative and quantitative observations, the analysis shows that, in symmetrical communication, the emphasis is on the blogger’s subjective interpretation of legal texts and on his role as knowledge disseminator, as indicated by the predominance of epistemic modality. In asymmetrical communication, on the other hand, the prevalence of deontic modality shifts the focus on to the reader as addressee of the advice, instructions and information provided by the legal expert.

scholarly journals Fabrication of Sio2-based microcantilevers by anisotropic chemical etching of (100) single crystal Si

2007 ◽  
Vol 72 (11) ◽  
pp. 1127-1138 ◽  
Author(s):  
Vesna Jovic ◽  
Jelena Lamovec ◽  
Mirjana Popovic ◽  
Zarko Lazic
Keyword(s):  
Aqueous Solution ◽  
Single Crystal ◽  
Silicon Substrate ◽  
Chemical Etching ◽  
Si Substrate ◽  
Si Wafer

The undercutting process of thermal SiO2 microcantilevers with different orientations on (100) Si wafer was studied. The silicon substrate was removed by anisotropic chemical etching with a 25 wt. % aqueous solution of TMAH or a 30 wt. % aqueous KOH solution at 80 ?C. It was found that [110] oriented cantilevers were undercutting frontally along the length and [100] oriented cantilevers experience undercutting along the width of the cantilever, which is a less time consuming process. The studies showed that the [100] orientation of SiO2 microbridges enables theirs fabrication on a (100) oriented Si substrate.

Microstructural Analysis for Si Wafer after CMG Process

2007 ◽  
Vol 329 ◽  
pp. 367-372 ◽  
Author(s):  
Sumio Kamiya ◽  
Hisao Iwase ◽  
Tetsuya Nagaike ◽  
Li Bo Zhou ◽  
Hiroshi Eda ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microstructural Analysis ◽  
X Ray Diffraction ◽  
Mechanical Grinding ◽  
Polishing Process ◽  
X Ray ◽  
Innovative Process ◽  
Dry Conditions ◽  
Solid Bulk ◽  
Si Wafer

The single crystal of Si is still one of the most important candidates among other materials including Single crystals of SiC, GaN, C(diamond) or compound semiconductors. The innovative process as called CMG(Chemo-Mechanical-Grinding) for Si wafer has been recently developed which is different from conventional CMP(Chemo-Mechanical-Polishing ) process. The CMG process can be done under dry conditions using CeO2 based solid bulk abrasives. The microstructures for surface and subsurface of Si single crystal after CMG process were analyzed using TEM/EDX, AFM, MFP-3D Microscope. The mechanism of CMG process was also investigated by X-ray diffraction and ICP chemical analysis using products by chemical reaction between Si and CeO2 abrasives. The results showed that Si single crystal after CMG had, 1) no defects even Si lattice revel or mechanical imperfections,2) better surface roughness as compared to CMP process. The CMG mechanism concluded that CeO2 reacted with Si producing Ce-Si-O amorphous phase.

Electroluminescence from single crystal Cu2O diodes

1979 ◽  
Vol 57 (7) ◽  
pp. 988-993 ◽  
Author(s):  
K. T. Chee ◽  
T. Keowsim ◽  
F. L. Weichman
Keyword(s):  
Single Crystal ◽  
Single Injection ◽  
Forward Bias ◽  
The Other ◽  
Double Injection ◽  
Injection Process ◽  
Current Voltage ◽  
Different Types ◽  
Current Voltage Characteristics ◽  
Transient Electroluminescence

We have measured the infrared electroluminescence in different types of single crystal Cu2O–Cu diodes under forward bias at various temperatures. Diodes which showed double-injection current-voltage characteristics in previous studies showed transient electroluminescence response at low currents and dc response at higher currents. On the other hand, diodes that showed the characteristics of single injection in previous studies showed transient electroluminescence response only. We have related the present studies on electroluminescence with the previous findings. Furthermore the present studies also revealed some information on the injection process. We have also discussed the differences and similarities between electroluminescence and photoluminescence of Cu2O.

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