Defect population and electrical properties of Ar+-laser crystallized polycrystalline silicon thin films

2000 ◽  
Vol 621 ◽  
Author(s):  
S. Christiansen ◽  
M. Nerding ◽  
C. Eder ◽  
G. Andrae ◽  
F. Falk ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electrical Properties ◽  
Process Parameters ◽  
Continuous Wave ◽  
Chemical Vapor ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Convergent Beam

ABSTRACTWe crystallize amorphous silicon (a-Si) layers (thicknesses: ∼300nm and ∼1300nm for comparison) that are deposited on glass substrates (Corning 7059) by low pressure chemical vapor deposition using a continuous wave Ar+-laser. We scan the raw beam with a diameter of ∼60νm in single traces and traces with varying overlap (30-60%). With optimized process parameters (fluence, scan velocity, overlap) we achieve polycrystalline Si with grains as wide as 100νm. The grain boundary population is dominated by first and second order twin boundaries as analyzed by electron backscattering analysis in the scanning electron microscope and convergent beam electron diffraction in the transmission electron microscope. These twins are known not (or only marginally) to degrade the electrical properties of the material. In addition to twins, dislocations and twin lamellae occur at varying densities (depending on grain orientation and process parameters). The recombination activity of the defects is analyzed by EBIC and according to these measurements crystallization receipts are defined that yield the reduction of electrically detrimental defects.

High Quality P-Doped μc-Si:H Films as Obtained by low Temperature Lpcvd of Disilane

1992 ◽  
Vol 283 ◽  
Author(s):  
C. Manfredotti ◽  
F. Fizzotti ◽  
G. Amato ◽  
L. Boarino ◽  
M. Abbas
Keyword(s):  
Chemical Vapor ◽  
Elastic Recoil ◽  
Volume Percentage ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Convergent Beam ◽  
P Type ◽  
High Degree

ABSTRACTBoth B- and P- doped silicon films deposited by Low Pressure Chemical Vapor Deposition (LPCVD) at 300 °C (p-type) and 420 °C (n-type) have been characterized by optical absorption, Photothermal Deflection Spectroscopy (PDS), resistivity, Elastic Recoil Detection Analysis (ERDA), Transmission Electron Microscopy (TEM), Convergent-Beam Electron Diffraction (CBED) and Raman spectroscopy measurements. P-doped films, deposited at large PH3 flux rates, show a high degree of microcrystallinity, indicating that P activates the nucleation process even at low temperatures. In this case, values of activation energy of resistivity as low as 0.007 eV were obtained. Both TEM and RAMAN results confirm a volume percentage of micro crystallinity above 30%. On the contrary, B-doped samples are not microcrystalline at least in the doping range investigated, and show a behaviour not different from samples deposited by PECVD.

scholarly journals Effect of the Nanoparticles on the Structure and Crystallization of Amorphous Silicon Thin Films Produced by rf Glow Discharge

1998 ◽  
Vol 13 (9) ◽  
pp. 2476-2479 ◽  
Author(s):  
E. Bertran ◽  
S. N. Sharma ◽  
G. Viera ◽  
J. Costa ◽  
P. St'ahel ◽  
...  
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Silicon Nanoparticles ◽  
Continuous Wave ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Electrical Measurements ◽  
Silicon Thin Films ◽  
Transmission Electron ◽  
Rf Glow Discharge

Thin films of nanostructured silicon (ns-Si:H) were deposited by plasma-enhanced chemical vapor deposition in the presence of silicon nanoparticles at 100 °C substrate temperature using a silane and hydrogen gas mixture under continuous wave (cw) plasma conditions. The nanostructure of the films has been demonstrated by diverse ways: transmission electron microscopy, Raman spectroscopy, and x-ray diffraction, which have shown the presence of ordered silicon clusters (1–2 nm) embedded in an amorphous silicon matrix. Because of the presence of these ordered domains, the films crystallize faster than standard hydrogenated amorphous silicon samples, as evidenced by electrical measurements during the thermal annealing.

A New Quantitative Roughness Measurement and its Application in the Polysilicon/Silicon Dioxide Interface

1992 ◽  
Vol 280 ◽  
Author(s):  
Su-Heng Lin ◽  
Miltiadis K. Hatalis
Keyword(s):  
Silicon Dioxide ◽  
Chemical Vapor ◽  
Interface Roughness ◽  
Height Distribution ◽  
Cross Sectional ◽  
Silicon Thin Films ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
High Temperature Processing

ABSTRACTA quantitative approach for characterizing the interface roughness between two materials by cross sectional transmission electron microscopy (XTEM) is proposed. This approach is based on obtaining an interface height distribution curve (IHDC). The interface roughness can be characterized quantitatively by extracting from IHDC three parameters: the mean, median and maximum interface height. This new method has been applied in the characterization of the interface between thermally grown silicon dioxide and polycrystalline silicon thin films deposited by low pressure chemical vapor deposition. It is shown that high temperature processing yields an interface that has higher roughness.

Influence of Hydrogen Dilution on Electrical Properties of Amorphous Silicon Thin Films Deposited on Glass Substrates

2011 ◽  
Vol 221 ◽  
pp. 117-122
Author(s):  
Ying Ge Li ◽  
Dong Xing Du
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Thin Layers ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Hydrogen Dilution

Thin film Amorphous Silicon materials have found wide application in photovoltaic industry. In this paper, thin layers (around 300nm) of intrinsic hydrogenated amorphous silicon (a-Si:H) are fabricated on glass (Corning Eagle2000TM) substrates by employing plasma enhanced chemical vapor deposition (PECVD) system with gas sources of silane and hydrogen. The deposited thin films are proven to be material of amorphous silicon by Raman spectroscopy measurement and their electronic transport properties are thoroughly characterized in terms of photoconductivity, dark conductivity and photo response. The effect of Hydrogen dilution on electrical properties are investigated for a-Si:H thin films deposited in the temperatures range of 150~200°C. Results indicate that a-Si:H thin films on glass substrate owns device-quality electrical properties and could be applied on fabricating thin film solar cells as the absorber layer material and on other photovoltaic or photo electronic devices.

Measurement of lattice parameter at the nanometer scale using convergent-beam microdiffraction from a thermal emission source

1993 ◽  
Vol 51 ◽  
pp. 690-691
Author(s):  
W. T. Pike
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Thermal Emission ◽  
Lattice Parameter ◽  
Scanning Transmission Electron Microscope ◽  
Emission Source ◽  
Device Structure ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Convergent Beam

With the advent of crystal growth techniques which enable device structure control at the atomic level has arrived a need to determine the crystal structure at a commensurate scale. In particular, in epitaxial lattice mismatched multilayers, it is of prime importance to know the lattice parameter, and hence strain, in individual layers in order to explain the novel electronic behavior of such structures. In this work higher order Laue zone (holz) lines in the convergent beam microdiffraction patterns from a thermal emission transmission electron microscope (TEM) have been used to measure lattice parameters to an accuracy of a few parts in a thousand from nanometer areas of material.Although the use of CBM to measure strain using a dedicated field emission scanning transmission electron microscope has already been demonstrated, the recording of the diffraction pattern at the required resolution involves specialized instrumentation. In this work, a Topcon 002B TEM with a thermal emission source with condenser-objective (CO) electron optics is used.

Growth of Si1−xGex, Strained Layers Using Atmospheric-Pressure CVD

1991 ◽  
Vol 220 ◽  
Author(s):  
F. Namavar ◽  
J. M. Manke ◽  
E. P. Kvam ◽  
M. M. Sanfacon ◽  
C. H. Perry ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Defect Density ◽  
Chemical Vapor ◽  
Good Growth ◽  
X Ray Diffraction ◽  
Strained Layers ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Film Defect

ABSTRACTThe objective of this paper is to demonstrate the epitaxial growth of SiGe strained layers using atmospheric-pressure chemical vapor deposition (APCVD). We have grown SiGe layers with various thicknesses and Ge concentrations at temperatures ranging from 800–1000°C. The samples were studied using a variety of methods, including transmission electron microscopy (TEM), high resolution X-ray diffraction (HRXRD) and Raman spectroscopy (RS). Both HRXRD and RS results indicate that samples with about 10% Ge and a thickness of about 1000 Å are almost fully strained. TEM analyses of these samples indicate a film defect density less than 105/cm2. SIMS results indicate that the oxygen concentration in the epitaxial layers is lower than that found in CZ substrates.Our analyses also indicate that as-grown epitaxial Ge layers several microns thick have a defect density less than 107/cm2. The relatively low defect density in both SiGe and Ge layers grown on Si has been attributed to far higher dislocation glide velocity at the relatively elevated growth temperatures employed in CVD and to very good growth cleanliness.

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