Direct Bonding of Silicon Wafers with Simultaneous Dopant Diffusion

2001 ◽  
Vol 681 ◽  
Author(s):  
Igor V. Grekhov ◽  
Tatiana S. Agrunova ◽  
Lioudmila S. Kostina ◽  
Natalia M. Shmidt ◽  
Helmut Föll ◽  
...  
Keyword(s):  
Bonding Interface ◽  
Silicon Surfaces ◽  
Structural Quality ◽  
Water Molecules ◽  
Large Area ◽  
Type Layer ◽  
P Type ◽  
First Time ◽  
Wafer Surfaces

ABSTRACTBonding of silicon surfaces in aqueous solution of compounds containing III and IV impurities was performed for the first time. It was observed that the presence of aluminum at the bonding interface improved structural quality of the interface. This phenomenon is explained by the increase of the contact area due to Al-OH group sandwiched between the water molecules adsorbed at hydrophilic wafer surfaces at the first bonding stage. The incorporation of Al produces a p-type layer and the I/V characteristics of the resultant np+n diodes is shown not to be influenced by the presence of the bonding interface. The technique developed could be advantageous for the design of multi-layer large area semiconductor devices.

Improved Passivation of a-Si:H / c-Si Interfaces Through Film Restructuring

2008 ◽  
Vol 1066 ◽  
Author(s):  
Michael Zanoni Burrows ◽  
U. K. Das ◽  
S. Bowden ◽  
S. S. Hegedus ◽  
R. L. Opila ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Silicon Surfaces ◽  
Initial Surface ◽  
Effective Lifetime ◽  
Bonding Structure ◽  
First Time ◽  
Post Deposition

ABSTRACTThe as-deposited passivation quality of amorphous silicon films on crystalline silicon surfaces is dependent on deposition conditions and resulting hydrogen bonding structure. However the initial surface passivation can be significantly improved by low temperature post-deposition anneal. For example an improvement in effective lifetime from 780 μsec as-deposited to 2080 μsec post-anneal is reported in the present work. This work probes the hydrogen bonding environment using monolayer resolution Brewster angle transmission Fourier transform infrared spectroscopy of 100 Å thick films. It is found that there is significant restructuring at the a-Si:H / c-Si interface upon annealing and a gain of mono-hydride bonding at the c-Si surface is detected. Calculations show an additional 3.56 − 4.50 × 1014 cm−2 mono-hydride bonding at c-Si surface due to annealing. The estimation of the surface hydride oscillator strength in transmission mode is reported for the first time to be 7.2 × 10−18 cm on Si (100) surface and 7.5 × 10−18 cm on Si (111).

scholarly journals Evaluating Differences in Elastic Modulus of Regenerated and Uninjured Mouse Digit Bone through microCT Density-Elasticity Calculation and Nanoindentation Testing

2021 ◽  
Author(s):  
Kevin F Hoffseth ◽  
Emily Busse ◽  
Michelle Lacey ◽  
Mimi C Sammarco
Keyword(s):  
Elastic Modulus ◽  
De Novo ◽  
The Elderly ◽  
Cost Of Care ◽  
Bone Architecture ◽  
Structural Quality ◽  
Small Scale ◽  
Mineral Density ◽  
First Time

Bone is an essential, healing structure in vertebrates that ensures daily function. However, the regenerative capacity of bone declines with age, compromising quality of life in the elderly and increasing cost of care. Here, for the first time, the elasticity of regenerated bone in a mouse digit amputation model is evaluated in order to better investigate biomechanics of skeletal regeneration. Amputation of the distal one third of the digit (third phalangeal element P3) results in de novo regeneration of the digit, where analyzing the structural quality of this regenerated bone is a challenging task due to its small scale and triangular shape. To date, the evaluation of structural quality of the P3 bone has primarily focused on mineral density and bone architecture. This work describes an image-processing based method for assessment of elasticity in the whole P3 bone by using microcomputed tomography-generated mineral density data to calculate spatially discrete elastic modulus values across the entire P3 bone volume. Further, we validate this method through comparison to nanoindentation-measured values for elastic modulus. Application to a set of regenerated and unamputated digits shows that regenerated bone has a lower elastic modulus compared to the uninjured digit, with a similar trend for experimental hardness values. This method will be impactful in predicting and evaluating the regenerative outcomes of potential treatments and heightens the utility of the P3 regenerative model.

Change of the Characterization Techniques as Progress of CuInSe2-Based Thin-Film PV Technology

2012 ◽  
Vol 725 ◽  
pp. 165-170
Author(s):  
Katsumi Kushiya ◽  
Hiroki Sugimoto ◽  
Yoshiyuki Chiba ◽  
Yoshiaki Tanaka ◽  
Hideki Hakuma
Keyword(s):  
Thin Film ◽  
Integrated Circuits ◽  
Limited Information ◽  
Large Area ◽  
Area Efficiency ◽  
Characterization Techniques ◽  
First Time ◽  
Film Form ◽  
Comprehensive Characterization

In the CuInSe2(CIS)-based thin-film PV technology, various characterization techniques have been applied to measure the composition, crystal structure, depth profile and defect chemistry and so on, since Boeing Aerospace, for the first time, has come to the 10 % milestone in a thin-film form in 1980 by fabricating a very small single cell with top grids. More advanced and comprehensive characterization techniques are being applied after over 18 % total-area efficiency was consistently achieved employing the “three stage method”, which was developed by National Renewable Energy Laboratory (NREL). Comparing to the CIS-based absorber, there are not so many researches to investigate the absorber/buffer interface because the buffer is too thin to analyse separately and precisely and there are quite limited information on reaction pathways and composition of the buffer layer. However, in order to achieve the aperture-area efficiency of over 18 % on over 800cm2-sized large-area integrated circuits, it is remarkably important how to enhance the quality of absorber/buffer interface. Therefore, analytical works to understand how to improve the FF should tend to be more and more important.

Normal Incidence Photoresponse as a Function of Well Width in P-Type GaAs/AlGaAs Multi-Quantum Wells

1996 ◽  
Vol 450 ◽  
Author(s):  
G. J. Brown ◽  
M. A. Capano ◽  
S. M. Hegde ◽  
K. Eyink ◽  
F. Szmulowicz
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Normal Incidence ◽  
Light Hole ◽  
Structural Quality ◽  
Hole State ◽  
X Ray Diffraction ◽  
Optimization Study ◽  
P Type

ABSTRACTWe have performed an optimization study of the mid-infrared photoresponse of p-type GaAs/AlGaAs Quantum Well Infrared Photodetectors (QWIPs) designed for normal incidence detection. In these p-type quantum wells, normal incidence absorption is allowed (by the dipole selection rules for optical transitions) especially for transitions from the heavy-hole ground state to the second light-hole state. Previous theoretical modeling predicted that this transition will produce the strongest bound-to-continuum infrared absorption when the second light-hole state is located very near the top of the GaAs quantum well. For AlGaAs barrier layers with 30% aluminum, our modeling showed that a well width between 45Å and 50Å would optimize the normal incidence photoresponse of this p-type QWIP. In this work, photore^oonse spectra are reported for well widths ranging from 40Å to 65Å. A series of samples were tudied in which only the GaAs well width was varied in two monolayer increments, from 11 to 20 monolayers. Photoluminescence and X-ray diffraction measurements were used to verify the composition, well width, and structural quality of each sample. This study verified that the spectral range of the normal incidence photoresponse is narrower, as predicted by theory, for well widths in which the second light-hole state approaches the top of the valence band well.

scholarly journals Влияние разориентации подложки и ее предварительного травления на структурные и оптические свойства интегрированных гетероструктур GaAs/Si(100), полученных методом газофазной эпитаксии

2018 ◽  
Vol 52 (8) ◽  
pp. 881
Author(s):  
П.В. Середин ◽  
Д.Л. Голощапов ◽  
Д.С. Золотухин ◽  
А.С. Леньшин ◽  
А.Н. Лукин ◽  
...  
Keyword(s):  
Gaas Layer ◽  
Structural Quality ◽  
Preliminary Treatment ◽  
Relaxation Coefficient ◽  
Ir Reflectance ◽  
Antiphase Domains ◽  
First Time ◽  
Positive Effect ◽  
Good Agreement

AbstractIt is shown for the first time that the structural and optical functional characteristics of integrated GaAs/Si(100) heterostructures can be controlled by using misoriented Si(100) substrates and their preliminary etching. The growth of an epitaxial GaAs layer on a Si substrate without the formation of antiphase domains can be carried out on a substrate deviated from the (100) singular plane by an angle smaller than 4°–6° or without a transition layer of GaAs nanocolumns. Preliminary treatment of the silicon substrate by etching makes it possible to use it for the vapor-phase epitaxial growth of a single-crystal GaAs film with a considerably smaller relaxation coefficient, which has a positive effect on the structural quality of the film. These data are in good agreement with the results of IR reflectance spectroscopy and photoluminescence and ultraviolet spectroscopy. The features of the optical properties of integrated GaAs/Si(100) heterostructures in the infrared and ultraviolet spectral regions are also defined by the relaxation coefficient.

Large-Area Homoepitaxial Growth of Low-Doped Thick Epilayers for Power Devices with VBR > 4 kV

2009 ◽  
Vol 615-617 ◽  
pp. 77-80 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
Birgit Kallinger
Keyword(s):  
Layer Thickness ◽  
Surface Quality ◽  
Doping Concentration ◽  
Epitaxial Layers ◽  
Power Devices ◽  
Large Area ◽  
Homoepitaxial Growth ◽  
Different Types ◽  
First Time

In this paper we present results on the growth of low-doped thick epitaxial layers on 4° off-oriented 4H-SiC using a commercially available hot-wall multi-wafer CVD system. For the first time we show results of a low-doped full-loaded 73” run on 4° off-oriented substrates with a layer thickness of more than 70 µm. The target doping concentration of 1.2×1015 cm-3 is suitable for blocking voltages > 6 kV. Results on doping, thickness and wafer-to-wafer homogeneities are shown. The surface quality of the grown layers was characterized by AFM. The density of different types of dislocations was determined by Defect Selective Etching.

Correlation of Microstructural Properties With Thermoelectric Performance of Bi0.5Sb1.5Te3 Films Fabricated by Electroplating

2010 ◽  
Vol 1267 ◽  
Author(s):  
Elena Koukharenko ◽  
Xiaohong Li ◽  
Jekaterina Kuleshova ◽  
Marcel Fowler ◽  
Nicole Frety ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Microstructural Properties ◽  
Fine Grained ◽  
Electrodeposited Film ◽  
P Type ◽  
First Time ◽  
Very High

AbstractThis study shows for the first time, the correlation between the microstructural properties (chemical composition and its homogeneity) and the thermoelectric properties for p-type Bi0.5Sb1.5Te3 electroplated films (10-15 μm thickness). High microstructural quality of Bi0.5Sb1.5Te3 electroplated films (a close to stoichiometry chemical composition with its high homogeneity elements distribution) was achieved by using an additive in the plating solution (sodium ligninsulfonate) as a surfactant agent. A fine-grained microstructure of 280 nm to 1μm has been observed for these materials, which half that of the plated films without a surfactant. The thermoelectric properties of electrodeposited Bi0.5Sb1.5Te3 films obtained without microstructural optimisation, show modest Seebeck coefficient values of 20-120 μm/K, electrodeposited film with an optimised microstructure exhibits very high values of Seebeck coefficient of 220-300 μm/K.

PMMA direct exfoliation for rapid and organic free transfer of centimeter-scale CVD graphene

2D Materials ◽  
2021 ◽  
Author(s):  
Hewei Zhao ◽  
Xianqin Xing ◽  
Gehui Zhang ◽  
Wenyu Liu ◽  
Haoyu Dong ◽  
...  
Keyword(s):  
Graphene Film ◽  
Chemical Vapor ◽  
Complete Removal ◽  
Large Area ◽  
Pmma Layer ◽  
Cvd Graphene ◽  
Higher Carrier Mobility ◽  
P Type ◽  
First Time ◽  
Incomplete Domains

Abstract Despite the various techniques developed for the transfer of large area graphene grown by chemical vapor deposition (CVD), the conventional PMMA transferring technique has been widely applied in laboratories due to its convenience and economical cost. However, the complete removal of PMMA on graphene surface has become a troublesome, and the PMMA residue could degrade the properties of graphene significantly. We report here a facile water assisted technique to directly peel off the PMMA layer over centimeter-sized CVD graphene film for the first time. No organic solvents are involved in the whole transfer process. The transferred graphene film is clean and intact over large area because of the cooperative effect of the capillary force and the van der Waals force which facilitates the conformal contact between graphene film and the substrate. Various types of graphene samples (i.e. monolayer, multilayer, and incomplete domains) can be easily transferred to diverse substrates including silicon wafer, sapphire, and quartz with good integrity. The transferred graphene film is of high cleanliness, and the graphene transistors show higher carrier mobility and lower level of p-type doping comparing to the conventional wet transfer technique.

scholarly journals “The good, the bad, the weird”: Stone Age and Early Metal Period radiocarbon dates and chronology from the Karelian Isthmus, North-West Russia

2012 ◽  
Vol 39 (2) ◽  
pp. 101-121 ◽  
Author(s):  
Oula Seitsonen ◽  
Kerkko Nordqvist ◽  
Dmitrij Gerasimov ◽  
Sergei Lisitsyn
Keyword(s):  
Current Data ◽  
Stone Age ◽  
Karelian Isthmus ◽  
Large Area ◽  
Related Factors ◽  
Radiocarbon Dates ◽  
North West ◽  
Radiocarbon Chronology ◽  
First Time

Abstract In this paper all the Stone Age and Early Metal Period (ca. 8600 cal BC — 300 AD) radiocarbon dates from the Karelian Isthmus, Russia, are compiled and their archaeological usability assessed using a set of evaluation principles. The quality of radiometric dates from such a large area has rarely been methodologically examined in Finnish or North-West Russian archaeology, and is applied here for the first time on the present material. Special attention is given to the discussion on the deficiencies and limitations of the current data. Based on the 81 dates evaluated as useful, a tentative radiocarbon chronology is presented for the study area. This is generally in sequence with the chronologies of the nearby areas, but suggests some differences especially towards the end of Stone Age, as well as the presence of biases caused by taphonomic and research-related factors.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

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