Effects of Deposition Parameters on Crystallization of Pecvd Amorphous Silicon Films

1995 ◽  
Vol 403 ◽  
Author(s):  
Yaozu Wang ◽  
Reece Kingi ◽  
Osama O. Awadelkarim ◽  
Stephen J. Fonash
Keyword(s):  
Grain Size ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Precursor Film ◽  
Furnace Annealing ◽  
Glass Substrates ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Si Films

AbstractPlasma-enhanced chemical vapor deposition was used to deposit a-Si:H thin films (∼ 1000 Å) at various temperatures below 300°C on Coming 7059 glass substrates using a silane-based plasma. These films were used as precursor materials to produce solid phase crystallized polycrystalline silicon (poly-Si) by conventional furnace annealing at 600°C in N2 ambient. The precursor a-Si and final poly-Si films were examined using spectroscopic ellipsometry and transmission electron microscopy. Precursor film deposition temperatures were found to affect the void density in the a-Si film and grain size in the resulting poly-Si film with lower deposition temperatures leading to higher void density in the a-Si film and larger grain size in the poly-Si film.

Grain size, Grain Uniformity, and (111) Texture Enhancement by Solid-phase Crystallization of F- and C-implanted SiGe Films

2000 ◽  
Vol 15 (7) ◽  
pp. 1630-1634 ◽  
Author(s):  
A. Rodríguez ◽  
J. Olivares ◽  
C. González ◽  
J. Sangrador ◽  
T. Rodríguez ◽  
...  
Keyword(s):  
Grain Size ◽  
Vapor Deposition ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Grain Sizes ◽  
Pressure Chemical ◽  
Film Microstructure ◽  
Si Films ◽  
Size Dispersion

The crystallization kinetics and film microstructure of poly-SiGe layers obtained by solid-phase crystallization of unimplanted and C- and F-implanted 100-nm-thick amorphous SiGe films deposited by low-pressure chemical vapor deposition on thermally oxidized Si wafers were studied. After crystallization, the F- and C-implanted SiGe films showed larger grain sizes, both in-plane and perpendicular to the surface of the sample, than the unimplanted SiGe films. Also, the (111) texture was strongly enhanced when compared to the unimplanted SiGe or Si films. The crystallized F-implanted SiGe samples showed the dendrite-shaped grains characteristic of solid-phase crystallized pure Si. The structure of the unimplanted SiGe and C-implanted SiGe samples consisted of a mixture of grains with well-defined contour and a small number of quasi-dendritic grains. These samples also showed a very low grain-size dispersion.

Modifying Crystallographic Orientations of Polycrystalline Si Films Using Ion Channeling

1984 ◽  
Vol 35 ◽  
Author(s):  
K. T-Y. Kung ◽  
R. B. Ivepson ◽  
R. Reif
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Silicon On Insulator ◽  
Furnace Annealing ◽  
Ion Channeling ◽  
Amorphous Substrates ◽  
Pressure Chemical ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTPolycrystalline silicon films 4800 Å thick deposited via low pressure chemical vapor deposition on oxidized silicon wafers have been amorphized by silicon ion implantation and subsequently recrystallized at 700°C. Due to channeling of the ions through grains whose <110> axes were sufficiently parallel to the beam, these grains survived the implantation step and acted as seed crystals for the solid-phase epitaxial regrowth of the film. This work suggests the feasibility of combining ion implantation and furnace annealing to generate large-grain, uniformly oriented polycrystal1ine films on amorphous substrates. It is a potential low-temperature silicon-on-insulator technology.

Thin-Film Transistors Fabricated With Poly-Si Films Crystallized by Microwave Annealing

1998 ◽  
Vol 508 ◽  
Author(s):  
YongWoo Choi ◽  
JeongNo Lee ◽  
TaeWoong Jang ◽  
ByungTae Ahn
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Thin Film Transistors ◽  
Solid Phase ◽  
Low Cost ◽  
Solid Phase Crystallization ◽  
Furnace Annealing ◽  
Microwave Annealing ◽  
Si Films ◽  
Better Than

AbstractSolid phase crystallization has the advantages of low cost and excellent uniformity but the crystallization temperature is too high to use glass as a substrate. Using microwave annealing, we crystallized a-Si films at 550 °C within 3 h, which is much shorter than the annealing time at 600 °C of furnace annealing. We fabricated TFTs with poly-Si films crystallized by microwave annealing at low temperature and obtained the characteristics slightly better than or at least comparable to the TFTs by furnace annealing in spite of smaller grain size. This may be due to the improvement of surface roughness of poly-Si film. The poly-Si TFTs with PECVD a-Si film showed better characteristics than the TFTs with LPCVD a-Si film because of larger grain size and smoother Si/SiO2 interface.

Improvement of Grain Size by Crystallization of Double-Layer Amorphous Silicon Films

1994 ◽  
Vol 345 ◽  
Author(s):  
Dae Gyu Moon ◽  
Jeong No Lee ◽  
Ho Bin Im ◽  
Byung Tae Ahn ◽  
Kee Soo Nam ◽  
...  
Keyword(s):  
Grain Size ◽  
Double Layer ◽  
Nucleation Rate ◽  
Incubation Time ◽  
Deposition Temperature ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Double Layers ◽  
Nucleation Sites ◽  
Si Films

AbstractWe investigated the solid phase crystallization (SPC) behavior of 1000 Å amorphous Si (a- Si) films deposited by plasma enhanced chemical vapor deposition (PECVD) at various temperatures and were able to enhance the grain size of the crystallized polysilicon films using double layers of a-Si filns. The deposition temperature of monolayer a-Si films varied from 200 to 400 °C and the films were recrystallized at 600 °C in nitrogen. As the deposition temperature increased, the incubation time was decreased and both the nucleation rate and growth rate were increased. Especially, the nucleation rate strongly depended on the deposition temperature.Since the Si-SiO2 interface provides a large number of nucleation sites, it is desirable to suppress nucleation at the interface. As an idea we employed a structure with double layer a-Si films. The bottom a-Si layer deposited at lower temperature could suppress the nucleation at the Si-SiO2 interface while the top a-Si layer deposited at higher temperature could nucleate with a smaller number of nucleation sites. The incubation time and transformation behavior were determined by the deposition temperature of the top layer. As an example, the grain size of the double layer film deposited sequentially at 150 °C and 200 °C enhanced to 1.8 μm while that of the monolayer film deposited at 200 °C was 1.4 μm.

Silicon Thin Film Growth by Pulsed Plasma CVD under Near-Atmospheric Pressure

2005 ◽  
Vol 891 ◽  
Author(s):  
Hirotatsu Kitabatake ◽  
Maki Suemitsu ◽  
Setsuo Nakajima ◽  
Tsuyoshi Uehara ◽  
Yasutake Toyoshima
Keyword(s):  
Atmospheric Pressure ◽  
Film Growth ◽  
Chemical Vapor ◽  
Pulsed Plasma ◽  
Silicon Thin Film ◽  
Cross Sectional ◽  
Raman Scattering Spectroscopy ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Si Films

ABSTRACTSi Plasma-enhanced chemical vapor deposition (PECVD) at a near-atmospheric pressure (NAP) of 500 Torr has been conducted by using a pulsed-electric-field based NAP-PECVD system. At a growth temperature of 180°C, poly-Si films with a high Raman ratio of 7.4 are obtained on glass substrates, while epitaxial-like growth occurs when Si(100) substrates are employed, as confirmed by Raman-scattering spectroscopy, X-ray diffraction, and a cross-sectional transmission-electron microscopy.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Developing Monolithically Integrated CdTe Devices Deposited by AP-MOCVD

2013 ◽  
Vol 1538 ◽  
pp. 275-280
Author(s):  
S.L. Rugen-Hankey ◽  
V. Barrioz ◽  
A. J. Clayton ◽  
G. Kartopu ◽  
S.J.C. Irvine ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Aluminosilicate Glass ◽  
Organic Chemical ◽  
Large Area ◽  
Monolithically Integrated ◽  
Glass Substrates ◽  
Laser Scribing

ABSTRACTThin film deposition process and integrated scribing technologies are key to forming large area Cadmium Telluride (CdTe) modules. In this paper, baseline Cd1-xZnxS/CdTe solar cells were deposited by atmospheric-pressure metal organic chemical vapor deposition (AP-MOCVD) onto commercially available ITO coated boro-aluminosilicate glass substrates. Thermally evaporated gold contacts were compared with a screen printed stack of carbon/silver back contacts in order to move towards large area modules. P2 laser scribing parameters have been reported along with a comparison of mechanical and laser scribing process for the scribe lines, using a UV Nd:YAG laser at 355 nm and 532 nm fiber laser.

scholarly journals Characterization of Defects and Stress in Polycrystalline Silicon Thin Films on Glass Substrates by Raman Microscopy

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Kuninori Kitahara ◽  
Toshitomo Ishii ◽  
Junki Suzuki ◽  
Takuro Bessyo ◽  
Naoki Watanabe
Keyword(s):  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Solid Phase ◽  
Raman Microscopy ◽  
Laser Crystallization ◽  
Local Vibration ◽  
Optical Phonon Mode ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Si Films

Raman microscopy was applied to characterize polycrystalline silicon (poly-Si) on glass substrates for application as thin-film transistors (TFTs) integrated on electronic display panels. This study examines the crystallographic defects and stress in poly-Si films grown by industrial techniques: solid phase crystallization and excimer laser crystallization (ELC). To distinguish the effects of defects and stress on the optical-phonon mode of the Si–Si bond, a semiempirical analysis was performed. The analysis was compared with defect images obtained through electron microscopy and atomic force microscopy. It was found that the Raman intensity for the ELC film is remarkably enhanced by the hillocks and ridges located around grain boundaries, which indicates that Raman spectra mainly reflect the situation around grain boundaries. A combination of the hydrogenation of films and the observation of the Si-hydrogen local-vibration mode is useful to support the analysis on the defects. Raman microscopy is also effective for detecting the plasma-induced damage suffered during device processing and characterizing the performance of Si layer in TFTs.

Polycrystalline Si Films Fabricated by Low Temperature Selective Nucleation and Solid Phase Epitaxy Process

1997 ◽  
Vol 485 ◽  
Author(s):  
Claudine M. Chen ◽  
Harry A. Atwater
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Crystal Growth ◽  
Incubation Time ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Grain Sizes ◽  
Random Nucleation ◽  
Nucleation Sites ◽  
Si Films

AbstractWith a selective nucleation and solid phase epitaxy (SNSPE) process, grain sizes of 10 μm have been achieved to date at 620°C in 100 nrm thick silicon films on amorphous SiO2, with potential for greater grain sizes. Selective nucleation occurs via a thin film reaction between a patterned array of 20 rnm thick indium islands which act as heterogeneous nucleation sites on the amorphous silicon starting material. Crystal growth proceeds by lateral solid phase epitaxy from the nucleation sites, during the incubation time for random nucleation. The largest achievable grain size by SNSPE is thus approximately the product of the incubation time and the solid phase epitaxy rate. Electronic dopants, such as B, P, and Al, are found to enhance the solid phase epitaxy rate and affect the nucleation rate.

Polycrystalline Silicon Films Formed by Solid-Phase Crystallization of Amorphous Silicon: the Substrate Effects on Crystallization Kinetics and Mechanism

1996 ◽  
Vol 424 ◽  
Author(s):  
Y.-H. Song ◽  
S.-Y. Kang ◽  
K. I. Cho ◽  
H. J. Yoo ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Substrate Effects ◽  
Random Nucleation ◽  
Pressure Chemical ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Induced Crystallization

AbstractThe substrate effects on the solid-phase crystallization of amorphous silicon (a-Si) have been extensively investigated. The a-Si films were prepared on two kinds of substrates, a thermally oxidized Si wafer (SiO2/Si) and a quartz, by low-pressure chemical vapor deposition (LPCVD) using Si2H6 gas at 470 °C and annealed at 600 °C in an N2 ambient for crystallization. The analysis using XRD and Raman scattering shows that crystalline nuclei are faster formed on the SiO2/Si than on the quartz, and the time needed for the complete crystallization of a-Si films on the SiO2/Si is greatly reduced to 8 h from ˜15 h on the quartz. In this study, it was first observed that crystallization in the a-Si deposited on the SiO2/Si starts from the interface between the a-Si film and the thermal oxide of the substrate, called interface-induced crystallization, while random nucleation process dominates on the quartz. The very smooth surface of the SiO2/Si substrate is responsible for the observed interface-induced crystallization of a-Si films.

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