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.

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.

Residual Ion Implantation Damage at Source/Drain Junctions of Excimer Laser Annealed Polycrystalline Silicon Thin Film Transistor

2002 ◽  
Vol 715 ◽  
Author(s):  
Kee-Chan Park ◽  
Jae-Shin Kim ◽  
Woo-Jin Nam ◽  
Min-Koo Han
Keyword(s):  
Thin Film ◽  
Ion Implantation ◽  
Excimer Laser ◽  
Polycrystalline Silicon ◽  
Thin Film Transistor ◽  
Silicon Layer ◽  
Silicon Thin Film ◽  
Cross Sectional ◽  
Implantation Damage ◽  
Transmission Electron

AbstractResidual ion implantation damage at source/drain junctions of excimer laser annealed polycrystalline silicon (poly-Si) thin film transistor (TFT) was investigated by high-resolution transmission electron microscopy (HR-TEM). Cross-sectional TEM observation showed that XeCl excimer laser (λ=308 nm) energy decreased considerably at the source/drain junctions of top-gated poly-Si TFT due to laser beam diffraction at the gate electrode edges and that the silicon layer amorphized by ion implantation, was not completely annealed at the juncions. The HR-TEM observation showed severe lattice disorder at the junctions of poly-Si TFT.

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.

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.

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.

Effects of Silicon Implantation and Processing Temperature on Performance of Polycrystalline Silicon Thin-Film Transistors Fabricated from Low Pressure Chemical Vapor Deposited Amorphous Silicon

1987 ◽  
Vol 106 ◽  
Author(s):  
Anne Chiang ◽  
Tiao Y. Huang ◽  
I-Wei Wu ◽  
Mark H. Zarzycki ◽  
Mario Fuse
Keyword(s):  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Device Fabrication ◽  
Processing Temperature ◽  
Efficient Removal ◽  
Silicon Thin Film ◽  
Chemical Vapor Deposited ◽  
Pressure Chemical ◽  
Higher Temperature ◽  
Silicon Implantation

ABSTRACTSilicon implantation has been found to dramatically enhance the grain size of polysilicon crystallized from LPCVD a-Si by retarding the nucleation process at the substrate interface. Corresponding improvement in TFT device performance was also observed, resulting in field effect mobilities as high as 109 cm2/Vs in devices with 1000 Å thick Si active layer. This effect is more significant in device fabrication processes with higher temperature, possibly due to increasingly efficient removal of implant related defects.

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