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.

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.

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.

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.

Polycrystalline Silicon Gettering Layers with Controlled Residual Stress

2013 ◽  
Vol 205-206 ◽  
pp. 284-289 ◽  
Author(s):  
David Lysáček ◽  
Petr Kostelník ◽  
Petr Pánek
Keyword(s):  
Residual Stress ◽  
Vapor Deposition ◽  
Polycrystalline Silicon ◽  
Opposite Sign ◽  
Chemical Vapor ◽  
Pressure Chemical ◽  
Novel Method ◽  
The Individual ◽  
Scanning Electron

We report on a novel method of low pressure chemical vapor deposition of polycrystalline silicon layers used for external gettering in silicon substrate for semiconductor applications. The proposed method allowed us to produce layers of polycrystalline silicon with pre-determined residual stress. The method is based on the deposition of a multilayer system formed by two layers. The first layer is intentionally designed to have tensile stress while the second layer has compressive stress. Opposite sign of the residual stresses of the individual layers enables to pre-determine the residual stress of the gettering stack. We used scanning electron microscopy for structural characterization of the layers and intentional contamination for demonstration of the gettering properties. Residual stress of the layers was calculated from the wafer curvature.

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.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

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.

Growth of Silicon-Germanium Alloys by Atmospheric-Pressure Chemical Vapor Deposition at Low Temperatures

1991 ◽  
Vol 220 ◽  
Author(s):  
P. D. Agnello ◽  
T. O. Sedgwick ◽  
M. S. Goorsky ◽  
J. Ott ◽  
T. S. Kuan ◽  
...  
Keyword(s):  
Silicon Germanium ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Significant Feature ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Silicon Growth ◽  
Silicon Germanium Alloys

ABSTRACTDichlorosilanc and germane were used to grow silicon-germanium alloys at temperatures as low as 550°C at atmospheric pressure. Germanium mole fractions as high as 44% were obtained and the layers exhibit smooth surface morphology. Silicon-gcrmanium/silicon multilayers with abrupt hctero-intcrfaccs have been achieved. Cross Section Transmission Electron Microscopy, (XTEM) and High Resolution X-Ray Diffraction, (HRXRD) characterization of the hetero-interface abruptness will be presented. Recent results on two-dimensional (2-D) hole mobility structures grown by this technique will also be reported. Selective growth of silicon-germanium on oxide patterned silicon wafers was also demonstrated. A significant feature of the selective deposition is the lack of faceting at the oxide sidcwall, which has been commonly observed in high temperature silicon growth.

Characterization of Polycrystalline Silicon Multilayers with thin Nitride/Oxide Films Using Spectroscopic Ellipsometry

1993 ◽  
Vol 324 ◽  
Author(s):  
L.M. Asinovsky
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Strongly Correlated ◽  
Si Substrate ◽  
Lorentz Oscillator ◽  
Pressure Chemical ◽  
Complete Recrystallization ◽  
Nitride Oxide

AbstractSpectroscopic ellipsometry has been used to characterize oxide/poly-Si/oxide with thin nitride/oxide layer. Films were deposited on Si substrate using low-pressure chemical vapor deposition (LPCVD) techniques. The measurements were taken at angles of incidence of 65 and 70 degrees in the wavelength range from 300 to 800 nm. The analysis of the data using effective medium and two-dimensional Lorentz oscillator approximations identified complete recrystallization of the poly-Si after annealing and and its transformation to µ c-Si. Three wafers taken at the sequential stages of the manufacturing process were studied. Although parameters of the thin nitride/oxide layers are strongly correlated, reasonable estimates of the thicknesses were found. The resuilts were consistent with the measured Auger electron spectroscopy (AES) profiles.

Sign in / Sign up

Export Citation Format

Share Document