scholarly journals X-Ray Interferometry of Volume Changes in C+Implanted Silicon

1973 ◽  
Vol 28 (5) ◽  
pp. 654-656b ◽  
Author(s):  
G. H. Schwuttke ◽  
K. Brack
Keyword(s):  
Silicon Carbide ◽  
Single Crystal ◽  
Amorphous Silicon ◽  
Radiation Damage ◽  
Single Crystal Silicon ◽  
High Energy ◽  
Volume Changes ◽  
Crystal Silicon ◽  
X Ray

High energy C+ implantation is used to construct a two crystal monolithic X-ray interferometer. The X-ray interferometer technique is applied to in-situ studies of radiation damage annealing in the interferometer. Volume changes in the crystal due to the transformation of single crystal silicon to amorphous silicon and due to the formation of silicon carbide are measured.

Polycapillary Optics for in Situ Diagnostics

1997 ◽  
Vol 502 ◽  
Author(s):  
F. A. Hofmann ◽  
N. Gao ◽  
S. M. Owens ◽  
W. M. Gibson ◽  
C. A. Macdonald ◽  
...  
Keyword(s):  
Measurement Techniques ◽  
Single Crystal Silicon ◽  
High Energy ◽  
Ex Situ ◽  
Glass Capillary ◽  
Accurate Analysis ◽  
Crystal Silicon ◽  
Polycapillary Optics ◽  
X Ray

ABSTRACTPolycapillary optics, shaped arrays consisting of hundreds of thousands of hollow glass capillary tubes, are used to redirect, collimate, or focus x-ray beams from conventional laboratory-based sources. Focused spot sizes as small as 20μm have been measured, with flux densities two orders of magnitude larger than that produced by pinhole or crossed slit collimation. Such flux increases have made possible faster and more sensitive x-ray fluorescence (XRF) and diffraction measurements to the extent that in situ measurements become possible. XRF data taken with a 12 W source were comparable to data taken with a 1.5 kW source. Ex situ diffraction and texture measurements on thin multilayered films and single crystal silicon demonstrate the tremendous experimental and analytical improvements made possible by polycapillary optics.With 0.5° and 2° focusing polycapillary x-ray optics, diffraction intensity gains of more than two orders of magnitude were measured on small Lysozyme protein crystals with exposure times an order of magnitude less than required by traditional measurement techniquesIn addition, the optics greatly reduce the background high energy Bremsstrahlung, permitting more accurate analysis of thin complex multilayer diffraction peaks. Rapid measurement times resulting from the application of these polycapillary optics, indicate tremendous possibilities for in situ process monitoring

scholarly journals The Influence of Wire Speed on Phase Transitions and Residual Stress in Single Crystal Silicon Wafers Sawn by Resin Bonded Diamond Wire Saw

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 429
Author(s):  
Tengyun Liu ◽  
Peiqi Ge ◽  
Wenbo Bi
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Phase Transitions ◽  
Single Crystal ◽  
Amorphous Silicon ◽  
Silicon Wafer ◽  
Single Crystal Silicon ◽  
Silicon Wafers ◽  
Crystal Silicon ◽  
Diamond Wire

Lower warp is required for the single crystal silicon wafers sawn by a fixed diamond wire saw with the thinness of a silicon wafer. The residual stress in the surface layer of the silicon wafer is the primary reason for warp, which is generated by the phase transitions, elastic-plastic deformation, and non-uniform distribution of thermal energy during wire sawing. In this paper, an experiment of multi-wire sawing single crystal silicon is carried out, and the Raman spectra technique is used to detect the phase transitions and residual stress in the surface layer of the silicon wafers. Three different wire speeds are used to study the effect of wire speed on phase transition and residual stress of the silicon wafers. The experimental results indicate that amorphous silicon is generated during resin bonded diamond wire sawing, of which the Raman peaks are at 178.9 cm−1 and 468.5 cm−1. The ratio of the amorphous silicon surface area and the surface area of a single crystal silicon, and the depth of amorphous silicon layer increases with the increasing of wire speed. This indicates that more amorphous silicon is generated. There is both compressive stress and tensile stress on the surface layer of the silicon wafer. The residual tensile stress is between 0 and 200 MPa, and the compressive stress is between 0 and 300 MPa for the experimental results of this paper. Moreover, the residual stress increases with the increase of wire speed, indicating more amorphous silicon generated as well.

scholarly journals Novel Abrasive-Impregnated Pads and Diamond Plates for the Grinding and Lapping of Single-Crystal Silicon Carbide Wafers

2021 ◽  
Vol 11 (4) ◽  
pp. 1783
Author(s):  
Ming-Yi Tsai ◽  
Kun-Ying Li ◽  
Sun-Yu Ji
Keyword(s):  
Silicon Carbide ◽  
Wear Rate ◽  
Single Crystal ◽  
Traditional Method ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Diamond Grit ◽  
Ceramic Binder

In this study, special ceramic grinding plates impregnated with diamond grit and other abrasives, as well as self-made lapping plates, were used to prepare the surface of single-crystal silicon carbide (SiC) wafers. This novel approach enhanced the process and reduced the final chemical mechanical planarization (CMP) polishing time. Two different grinding plates with pads impregnated with mixed abrasives were prepared: one with self-modified diamond + SiC and a ceramic binder and one with self-modified diamond + SiO2 + Al2O3 + SiC and a ceramic binder. The surface properties and removal rate of the SiC substrate were investigated and a comparison with the traditional method was conducted. The experimental results showed that the material removal rate (MRR) was higher for the SiC substrate with the mixed abrasive lapping plate than for the traditional method. The grinding wear rate could be reduced by 31.6%. The surface roughness of the samples polished using the diamond-impregnated lapping plate was markedly better than that of the samples polished using the copper plate. However, while the surface finish was better and the grinding efficiency was high, the wear rate of the mixed abrasive-impregnated polishing plates was high. This was a clear indication that this novel method was effective and could be used for SiC grinding and lapping.

Electronic Properties of Femtosecond Laser Induced Modified Spots on Single Crystal Silicon Carbide

2010 ◽  
Vol 645-648 ◽  
pp. 239-242 ◽  
Author(s):  
Takuro Tomita ◽  
M. Iwami ◽  
M. Yamamoto ◽  
M. Deki ◽  
Shigeki Matsuo ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Femtosecond Laser ◽  
Single Crystal ◽  
Specific Resistance ◽  
Single Crystal Silicon ◽  
Metal Contacts ◽  
Crystal Silicon ◽  
Current Voltage ◽  
Fs Laser ◽  
Current Voltage Characteristics

Femtosecond (fs) laser modification on single crystal silicon carbide (SiC) was studied from the viewpoints of electric conductivity. Fourier transform infrared (FTIR) spectroscopy was carried out on femtosecond laser modified area. The intensity decrease of reststrahlen band due to the modification was observed, and this decrease was explained by the degradation of crystallinity due to the laser irradiation. Polarization dependence of reststrahlen band was also observed on laser modified samples. Current-voltage characteristics and Hall measurements on fs-laser modified region were carried out by fabricating the metal contacts on the ion implanted areas. The specific resistance up to 5.9×10-2 m was obtained for fs-laser modified area.

Three Generations of Solar Cells

2021 ◽  
Vol 1165 ◽  
pp. 113-130
Author(s):  
Romyani Goswami
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Single Crystal ◽  
Amorphous Silicon ◽  
Cost Reduction ◽  
High Stability ◽  
Single Crystal Silicon ◽  
Nanocrystalline Silicon ◽  
Crystal Silicon

In photovoltaic system the major challenge is the cost reduction of the solar cell module to compete with those of conventional energy sources. Evolution of solar photovoltaic comprises of several generations through the last sixty years. The first generation solar cells were based on single crystal silicon and bulk polycrystalline Si wafers. The single crystal silicon solar cell has high material cost and the fabrication also requires very high energy. The second generation solar cells were based on thin film fabrication technology. Due to low temperature manufacturing process and less material requirement, remarkable cost reduction was achieved in these solar cells. Among all the thin film technologies amorphous silicon thin film solar cell is in most advanced stage of development and is commercially available. However, an inherent problem of light induced degradation in amorphous silicon hinders the higher efficiency in this kind of cell. The third generation silicon solar cells are based on nano-crystalline and nano-porous materials. Hydrogenated nanocrystalline silicon (nc-Si:H) is becoming a promising material as an absorber layer of solar cell due to its high stability with high Voc. It is also suggested that the cause of high stability and less degradation of certain nc-Si:H films may be due to the improvement of medium range order (MRO) of the films. During the last ten years, organic, polymer, dye sensitized and perovskites materials are also attract much attention of the photovoltaic researchers as the low budget next generation PV material worldwide. Although most important challenge for those organic solar cells in practical applications is the stability issue. In this work nc-Si:H films are successfully deposited at a high deposition rate using a high pressure and a high power by Radio Frequency Plasma Enhanced Chemical Vapor Deposition (RF PECVD) technique. The transmission electron microscopy (TEM) studies show the formations of distinct nano-sized grains in the amorphous tissue with sharp crystalline orientations. Light induced degradation of photoconductivity of nc-Si:H materials have been studied. Single junction solar cells and solar module were successfully fabricated using nanocrystalline silicon as absorber layer. The optimum cell is 7.1 % efficient initially. Improvement in efficiency can be achieved by optimizing the doped layer/interface and using Ag back contact.

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