Xrd and Xtem Investigation of Polycrystalline Silicon Carbide on Polycrystalline Silicon

1996 ◽  
Vol 444 ◽  
Author(s):  
S. Roy ◽  
C. A. Zorman ◽  
C. H. Wu ◽  
A. J. Fleischman ◽  
M. Mehregany
Keyword(s):  
Silicon Carbide ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Before And After ◽  
Pressure Chemical ◽  
Polysilicon Films ◽  
Sic Films

AbstractAtmospheric pressure chemical vapor deposition (APCVD) was used to grow silicon carbide (SiC) on as-deposited and annealed polycrystalline silicon (polysilicon) films which were deposited on oxidized Si wafers. X-ray diffraction (XRD) reveals that SiC films grown on asdeposited polysilicon have a (110) orientation. XRD performed on as-deposited polysilicon before and after SiC growth reveals that the orientation of polysilicon changes from (110) to a mixture of (110) and (11) during growth of 2 μm-thick SiC films. Cross-sectional transmission electron microscopy (XTEM) images of the SiC/polysilicon interface show that the SiC appears to be unaffected by the recrystallization of the underlying polysilicon during the SiC growth. XRD from samples of SiC grown on annealed polysilicon show that both films have (110) and (111) orientations. For SiC films grown on annealed polysilicon substrates, XTEM images show that the crystallinity of the annealed polysilicon substrate does not significantly change during SiC growth. Furthermore, an investigation of the SiC/annealed-polysilicon interface using selected area diffraction (SAD) shows that an epitaxial relationship exists between the polysilicon and SiC grains.

Variable Angle Spectroscopic Ellipsometric Characterization of Polycrystalline Silicon thin Film Multilayer Structures

1991 ◽  
Vol 238 ◽  
Author(s):  
Paul G. Snyder ◽  
Yi-Ming Xiong ◽  
John A. Woollam ◽  
Eric R. Krosche
Keyword(s):  
Polycrystalline Silicon ◽  
Composite Layer ◽  
Chemical Vapor ◽  
Silicon Thin Film ◽  
Cross Sectional ◽  
Additional Information ◽  
Variable Angle ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Annealing Effects

ABSTRACTVariable angle spectroscopie ellipsometry (VASE), a nondestructive optical technique, was used to characterize two different multilayer samples, each having a low-pressure chemical vapor deposited polycrystalline silicon (poly-Si) layer. Analysis of these samples by cross-sectional transmission electron microscopy (XTEM) revealed large changes in grain size, between the undoped, as-deposited, and doped, annealed poly-Si layers. Roughness at the top of the poly-Si layers was also observed by XTEM. These features, together with the other structure parameters (thickness and composition), were analyzed ellipsometrically by fitting the measured VASE spectra with appropriate multilayer models. Each composite layer (surface overlayer, interfacial layer, and poly-Si layer) was modeled as a physical mixture, using the Bruggeman effective medium approximation. The ellipsometrically determined thicknesses were in very good agreement with the corresponding results measured by XTEM. Furthermore, VASE analysis provided additional information about the relative fractions of the constituent materials in the different composite layers. Thus, it quantitatively characterized the surface and interracial properties, and also the doping and annealing effects on the microstructure of poly-Si layers.

Characterization of polycrystalline silicon carbide films grown by atmospheric pressure chemical vapor deposition on polycrystalline silicon

1998 ◽  
Vol 13 (2) ◽  
pp. 406-412 ◽  
Author(s):  
Christian A. Zorman ◽  
Shuvo Roy ◽  
Chien-Hung Wu ◽  
Aaron J. Fleischman ◽  
Mehran Mehregany
Keyword(s):  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Deposition Process ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polycrystalline Silicon Carbide ◽  
Pressure Chemical ◽  
Temperature Deposition ◽  
Sic Films

X-ray diffraction, transmission electron microscopy, and Rutherford backscattering spectroscopy were used to characterize the microstructure of polycrystalline SiC films grown on as-deposited and annealed polysilicon substrates. For both substrate types, the texture of the SiC films resembles the polysilicon at the onset of SiC growth. During the high temperature deposition process, the as-deposited polysilicon recrystallizes without influencing the crystallinity of the overlying SiC. An investigation of the SiC/polysilicon interface reveals that a heteroepitaxial relationship exists between polysilicon and SiC grains. From this study, a method to control the orientation of highly textured polycrystalline SiC films has been developed.

Growth of Polycrystalline Silicon Carbide on Thin Polysilicon Sacrificial Layers for Surface Micromachining Applications

2002 ◽  
Vol 741 ◽  
Author(s):  
R.F. Wiser ◽  
J. Chung ◽  
M. Mehregany ◽  
C.A. Zorman
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Polycrystalline Silicon ◽  
Sacrificial Layer ◽  
Chemical Vapor ◽  
Polycrystalline Silicon Carbide ◽  
Pressure Chemical ◽  
Sacrificial Layers ◽  
High Degree ◽  
Sic Films

ABSTRACTPolycrystalline silicon carbide (poly-SiC) films were deposited by atmospheric pressure chemical vapor deposition (APCVD) at epitaxial growth temperatures on planar, 100 nm-thick polysilicon sacrificial layers using two recipes that included or excluded a pre-growth carbonization step. Poly-SiC films grown using the carbonization-based recipe exhibited a relatively high degree of (111) 3C-SiC texture and had uniform, well-defined, void-free poly-SiC/polysilicon interfaces. In contrast, poly-SiC films grown without carbonization were randomly oriented, had numerous poly-SiC inclusions that sometimes completely penetrated the polysilicon underlayer, and had a higher surface roughness than the films grown with carbonization. Analysis of micromechanical clamped-clamped (C-C) beam resonators fabricated from films grown using the two differing recipes shows that the carbonization step is needed to protect the thin polysilicon sacrificial layer from voids and inclusions and thus maintain the proper spacing between the drive electrodes and the resonant beams.

The Effect of Temperature and Pressure on Residual Stress in LPCVD Polysilicon Films

1992 ◽  
Vol 276 ◽  
Author(s):  
D-G. Oei ◽  
S. L. McCarthy
Keyword(s):  
Residual Stress ◽  
Deposition Temperature ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Effect Of Temperature ◽  
Pressure Chemical ◽  
Polysilicon Films ◽  
Oriented Polycrystalline ◽  
Temperature And Pressure ◽  
Reduced Pressures

ABSTRACTMeasurements of the residual stress in polysilicon films made by Low Pressure Chemical Vapor Deposition (LPCVD) at different deposition pressures and temperatures are reported. The stress behavior of phosphorus (P)-ion implanted/annealed polysilicon films is also reported. Within the temperature range of deposition, 580 °C to 650 °C, the stress vs deposition temperature plot exhibits a transition region in which the stress of the film changes from highly compressive to highly tensile and back to highly compressive as the deposition temperature increases. This behavior was observed in films that were made by the LPCVD process at reduced pressures of 210 and 320 mTORR. At deposition temperatures below 590 °C the deposit is predominantly amorphous, and the film is highly compressive; at temperatures above 610 °C (110) oriented polycrystalline silicon is formed exhibiting high compressive residual stress.

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.

Novel Polycrystalline SiC Films Containing Nanoscale Through-Pores by Selective APCVD

2006 ◽  
Vol 527-529 ◽  
pp. 755-758
Author(s):  
L. Chen ◽  
Xiao An Fu ◽  
Christian A. Zorman ◽  
Mehran Mehregany
Keyword(s):  
Atmospheric Pressure ◽  
Polycrystalline Silicon ◽  
Electrochemical Etching ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Porous Structures ◽  
Porous Polycrystalline ◽  
Polycrystalline Silicon Carbide ◽  
Pressure Chemical ◽  
Sic Films

A selective atmospheric pressure chemical vapor deposition (APCVD) process has been developed to deposit porous polycrystalline silicon carbide (poly-SiC) thin films containing a high density of through-pores measuring 50 to 70 nm in diameter. The selective deposition process involves the formation of poly-SiC films on patterned SiO2/polysilicon thin film multilayers using a carbonization-based 3C-SiC growth process. This technique capitalizes on significant differences in the nucleation of poly-SiC on SiO2 and polysilicon surfaces in order to form mechanically-durable, chemically-stable, and well anchored porous structures, thus offering a simple and potentially more versatile alternative to direct electrochemical etching.

Grain Formation in Polycrystalline Silicon Films Deposition on SiO2 at Very Low Temperatures

1995 ◽  
Vol 377 ◽  
Author(s):  
Kun-Chih Wang ◽  
Ruo-Yu Wang ◽  
Tri-Rung Yew ◽  
Joseph J. Loferski ◽  
Huey-Liang Hwang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polycrystalline Silicon ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Cross Sectional ◽  
Plan View ◽  
Transmission Electron ◽  
Grain Formation

ABSTRACTThis paper describes the grain formation in very low temperature polycrystalline silicon (poly-Si) growth on SiO2. The silicon films were deposited by electron cyclotron resonance chemical vapor deposition with hydrogen dilution at 250°C and without any thermal annealing. The largest grain sizes observed in the poly-Si film is about 1 μm. The grains have a leaf-like shape as observed in plan-view transmission electron microscopy. The grain morphologies were determined by cross-sectional transmission electron microscopy and atomic force microscopy. Raman scattering spectrum was used to determine the crystalline fraction. X-ray diffraction patterns were used to study the film crystallinity. A simple model of grain formation is proposed.

Cross-Sectional Transmission Electron Microscopy of Defects in Beta Silicon Carbide Thin Films

1985 ◽  
Vol 46 ◽  
Author(s):  
C.H. Carter ◽  
J.A. Edmond ◽  
J.W. Palmour ◽  
J. Ryu ◽  
H.J. Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Vapor Deposition ◽  
Defect Structure ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Cross Sectional ◽  
Transmission Electron

AbstractTechniques have been developed at NCSU for fabricating cross-sectional transmission electron microscopy (XTEM) foils from monocrystalline beta silicon carbide thin films grown by chemical vapor deposition. The results of the TEM observations are utilized to discern the efficacy of the various processing parameters in terms of film quality and defect structure as well as oxidation, ion implantation and annealing procedures.

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