Silicon Devices Fabricated by Using Laser Irradiation Process

1981 ◽  
Vol 4 ◽  
Author(s):  
M. Tamura ◽  
N. Natsuaki ◽  
M. Miyao ◽  
M. Ohkura ◽  
F. Murai ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Active Layer ◽  
Laser Processing ◽  
Film Formation ◽  
Si Substrates ◽  
Advantages And Disadvantages ◽  
Silicon Devices ◽  
Formation Conditions ◽  
Si Films ◽  
Irradiation Process

ABSTRACTThe advantages and disadvantages of both pulsed and cw scanned laser processing for Si devices are discussed. In particular, adaptions of laser processes for MOSFETs and bipolar structures are described from the viewpoint of active layer annealing. Moreover, MOSFETs fabricated in laser induced grown Si films on Si substrates having SiO2 patterns by bridging epitaxy, are discussed, as a function of sample structures, film formation conditions and laser irradiation conditions.

Electron Energy Analysis of Germanium and Silica Layers on Silicon Substrates

1975 ◽  
Vol 33 ◽  
pp. 96-97
Author(s):  
R. W. Ditchfield ◽  
A. G. Cullis
Keyword(s):  
Epitaxial Growth ◽  
Electron Energy ◽  
Silicon Substrates ◽  
Secondary Phases ◽  
Si Substrates ◽  
Transmission Electron ◽  
Layer Structures ◽  
Si Films ◽  
Electron Energy Loss ◽  
Growth Centres

An energy analyzing transmission electron microscope of the Möllenstedt type was used to measure the electron energy loss spectra given by various layer structures to a spatial resolution of 100Å. The technique is an important, method of microanalysis and has been used to identify secondary phases in alloys and impurity particles incorporated into epitaxial Si films.Layers Formed by the Epitaxial Growth of Ge on Si Substrates Following studies of the epitaxial growth of Ge on (111) Si substrates by vacuum evaporation, it was important to investigate the possible mixing of these two elements in the grown layers. These layers consisted of separate growth centres which were often triangular and oriented in the same sense, as shown in Fig. 1.

Rapid Epitaxial Growth of Si and SiGe Mono-Crystalline Films on Silicon-on-Glass Substrates by Reactive CVD Using SiH4, GeH4, and F2

2012 ◽  
Vol 1426 ◽  
pp. 331-337
Author(s):  
Hiroshi Noge ◽  
Akira Okada ◽  
Ta-Ko Chuang ◽  
J. Greg Couillard ◽  
Michio Kondo
Keyword(s):  
Epitaxial Growth ◽  
Heating Temperature ◽  
Exothermic Reaction ◽  
Epitaxial Films ◽  
Si Substrates ◽  
Glass Substrates ◽  
Good Crystallinity ◽  
Crystalline Films ◽  
Si Films ◽  
First Time

ABSTRACTWe have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.

Role of grain boundaries in the epitaxial realignment of undoped and As-doped polycrystalline silicon films

1993 ◽  
Vol 8 (10) ◽  
pp. 2608-2612 ◽  
Author(s):  
C. Spinella ◽  
F. Benyaïch ◽  
A. Cacciato ◽  
E. Rimini ◽  
G. Fallico ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Structure ◽  
Native Oxide ◽  
Thermally Induced ◽  
Si Substrates ◽  
As Doping ◽  
Fine Grain ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Reduced Density

The early stages of the thermally induced epitaxial realignment of undoped and As-doped polycrystalline Si films deposited onto crystalline Si substrates were monitored by transmission electron microscopy. Under the effect of the heat treatment, the native oxide film at the poly-Si/c-Si interface begins to agglomerate into spherical beads. The grain boundary terminations at the interface are the preferred sites for the triggering of the realignment transformation which starts by the formation of epitaxial protuberances at these sites. This feature, in conjunction with the microstructure of the films during the first instants of the heat treatment, explains the occurrence of two different realignment modes. In undoped films the epitaxial protuberances, due to the fine grain structure, are closely distributed and grow together forming a rough interface moving toward the film's surface. For As-doped films, the larger grain size leaves a reduced density of realignment sites. Due to As doping some of these sites grow fast and form epitaxial columns that further grow laterally at the expense of the surrounding polycrystalline grains.

Transistors with a Profiled Active Layer Made by Hot-Wire Cvd

1998 ◽  
Vol 507 ◽  
Author(s):  
H. Meiling ◽  
A.M. Brockhoff ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Thin Film ◽  
Active Layer ◽  
Hot Wire ◽  
Semiconductor Interface ◽  
Cross Sectional ◽  
Silicon Matrix ◽  
Bias Stress ◽  
Silicon Devices ◽  
Transmission Electron ◽  
Conducting Research

ABSTRACTIn order to obtain stable thin-film silicon devices we are conducting research on the implementation of hot-wire CVD amorphous and polycrystalline silicon in thin-film transistors, TFFs. We present results on TFTs with a profiled active layer (deposited at ≥9 Å/s), and correlate the electrical properties with the structure of the silicon matrix at the insulator/semiconductor interface, as determined with cross-sectional transmission electron microscopy. Devices prepared with an appropriate H2 dilution of SiH4 show cone-shaped crystalline inclusions. These crystals start at the interface in some cases, and in others exhibit an 80nm incubation layer prior to nucleation. The crystals in the TFTs with the incubation layer are not cone-shaped, but are rounded off. The hot-wire CVD deposited devices exhibit a high fieldeffect mobility up to 1.5 cm2V−1s−l. Also, these devices have superior stability upon continuous gate bias stress, as compared to conventional glow-discharge α-Si:H TFTs. We ascribe this to a combination of enhanced structural order of the silicon and a low hydrogen content.

scholarly journals The Efficacy of a Diode Laser on Titanium Implants for the Reduction of Microorganisms That Cause Periimplantitis

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7215
Author(s):  
Anna Wawrzyk ◽  
Michał Łobacz ◽  
Agnieszka Adamczuk ◽  
Weronika Sofińska-Chmiel ◽  
Mansur Rahnama
Keyword(s):  
Laser Irradiation ◽  
Diode Laser ◽  
Fungal Species ◽  
Laser Wavelength ◽  
Titanium Implants ◽  
Isolation And Identification ◽  
Implant Surface ◽  
Streptococcus Constellatus ◽  
Surface Optical ◽  
Irradiation Process

The paper presents the optimisation of a safe diode laser irradiation process applied to the surface of titanium implants in order to reduce microbial numbers in the treatment of inflammation classified as periimplantitis. The study comprised isolation and identification of microorganisms inhabiting surfaces of dental implants, crowns, teeth and saliva from patients with fully symptomatic periimplantitis. Microorganisms were detected by a culture-dependent method and identified with the use of MALDI-TOF mass spectrometry. The isolated microorganisms were inoculated on the surface of a new implant and then irradiated by a diode laser (wavelength of 810 ± 10 nm) in one, two or three repetitions and biocidal efficacy was assessed. To evaluate impact of laser irradiation on roughness, morphology and structure of the implant surface, optical profilometry, scanning electron microscopy and optical microscopy were used. Examination of the tested surfaces and saliva revealed the presence of Gram-positive and Gram-negative bacteria and one fungal species. In all patients, cultures from the endosseous part of the implant revealed the presence of the pathogenic and pyogenic bacterium Streptococcus constellatus. In 13 out of 20 samples laser-irradiated in duplicate and triplicate, all microorganisms were eliminated. The irradiation used did not cause any changes in the properties of the implant surface.

Effect of Ge on SiC Film Morphology in SiC/Si Films Grown by MOCVD

1999 ◽  
Vol 572 ◽  
Author(s):  
W. L. Samey ◽  
L. Salamanca-Riba ◽  
P. Zhou ◽  
M. G. Spencer ◽  
C. Taylor ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Two Dimensional ◽  
High Quality ◽  
Flow Rates ◽  
Si Substrates ◽  
Cvd Growth ◽  
Polytype Transformation ◽  
Si Films ◽  
Sic Film ◽  
Sic Films

ABSTRACTSiC/Si films generally contain stacking faults and amorphous regions near the interface. High quality SiC/Si films are especially difficult to obtain since the temperatures usually required to grow high quality SiC are above the Si melting point. We added Ge in the form of GeH2 to the reactant gases to promote two-dimensional CVD growth of SiC films on (111) Si substrates at 1000°C. The films grown with no Ge are essentially amorphous with very small crystalline regions, whereas those films grown with GeH2 flow rates of 10 and 15 sccm are polycrystalline with the 3C structure. Increasing the flow rate to 20 sccm improves the crystallinity and induces growth of 6H SiC over an initial 3C layer. This study presents the first observation of spontaneous polytype transformation in SiC grown on Si by MOCVD.

Zone‐melting recrystallization of 3‐in.‐diam Si films on SiO2‐coated Si substrates

1982 ◽  
Vol 41 (2) ◽  
pp. 186-188 ◽  
Author(s):  
John C. C. Fan ◽  
B‐Y. Tsaur ◽  
R. L. Chapman ◽  
M. W. Geis
Keyword(s):  
Zone Melting ◽  
Si Substrates ◽  
Si Films
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