Solid-Phase Crystallization of Amorphous Si0.7Ge0.3/Si and Si/Si0.7Ge0.3 Bilayer Films on SiO2

1996 ◽  
Vol 424 ◽  
Author(s):  
Tae-Hoon Kim ◽  
Myung-Kwan Ryu ◽  
Jin-Won Kim ◽  
Chang-Soo Kim ◽  
Ki-Bum Kim
Keyword(s):  
Annealing Temperature ◽  
Defect Density ◽  
Solid Phase ◽  
Crystallization Rate ◽  
Grain Morphology ◽  
Solid Phase Crystallization ◽  
Bilayer Films ◽  
Average Grain Size ◽  
Average Size ◽  
Equiaxed Grains

AbstractWe have investigated the solid phase crystallization of a-(Si/Si0.7Ge0.3) and a-(Si0.7Ge0.3/Si) bilayer films deposited on SiO2 for an annealing temperature of 550 °C. It was found that, in case of a-(Si0.7Ge0 3/Si), nucleation of crystalline phases occurred at the free surface, while in a-(Si/Si0.7Ge0.3) crystalline phase nucleated at Si0.7Ge0.3/SiO2 interface. The crystallization rate of an a-(Si0.7Ge0.3/Si) is much slower than that of an a-(Si/Si0.7Ge0.3) films. After full crystallization, poly-(Si0.7Ge0.3/Si) has many equiaxed grains and the defect density of the upper Si0.7Ge0.3 was much lower than that of lower Si0.7 Ge0.3 in a poly-(Si/Si0.7Ge0.3) film whose grain morphology was elliptical. The average grain size of poly-(Si0.7Ge0.3/Si) was ˜7 μm and this film had strong (111) preferential orientation, while poly-(Si/Si0.7Ge0.3) had weak (311) or random oriented grains with the average size of˜0.3 μm.

Comparison Between Rapid Thermal and Furnace Annealing for A-Si Solid Phase Crystallization

1996 ◽  
Vol 424 ◽  
Author(s):  
Reece Kingi ◽  
Yaozu Wang ◽  
Stephen J. Fonash ◽  
Osama Awadelkarim ◽  
John Mehlhaff
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Growth Time ◽  
Crystallization Time ◽  
Solid Phase Crystallization ◽  
Furnace Annealing ◽  
Lower Growth ◽  
Transient Time

AbstractRapid thermal annealing and furnace annealing for the solid phase crystallization of amorphous silicon thin films deposited using PECVD from argon diluted silane have been compared. Results reveal that the crystallization time, the growth time, and the transient time are temperature activated, and that the resulting polycrystalline silicon grain size is inversely proportional to the annealing temperature, for both furnace annealing and rapid thermal annealing. In addition, rapid thermal annealing was found to result in a lower transient time, a lower growth time, a lower crystallization time, and smaller grain sizes than furnace annealing, for a given annealing temperature. Interestingly, the transient time, growth time, and crystallization time activation energies are much lower for rapid thermal annealing, compared to furnace annealing.We propose two models to explain the observed differences between rapid thermal annealing and furnace annealing.

Quantum State in Solid-Phase Crystallization of a-Si:H by FA

2010 ◽  
Vol 44-47 ◽  
pp. 4154-4156
Author(s):  
Rui Min Jin ◽  
Ding Zhen Li ◽  
Lan Li Chen ◽  
Xiang Ju Han ◽  
Jing Xiao Lu
Keyword(s):  
Thin Film ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Quantum States ◽  
Solid Phase Crystallization ◽  
Furnace Annealing ◽  
Conventional Furnace ◽  
Different Temperatures ◽  
Conventional Furnace Annealing ◽  
Electronic Microscope

Amorphous silicon films prepared by PECVD on glass substrate has been crystallized by conventional furnace annealing (FA) at different temperatures. From the Raman spectra and scanning electronic microscope (SEM), it is found that the thin film grain size present quantum states with annealing temperature.

Stress and Dopant Activation in Solid Phase Crystalized Si Films

1999 ◽  
Vol 558 ◽  
Author(s):  
A. Kaan Kalkan ◽  
Stephen J. Fonash
Keyword(s):  
Tensile Stress ◽  
Defect Density ◽  
Solid Phase ◽  
Structural Defects ◽  
Raman Shift ◽  
Solid Phase Crystallization ◽  
Dopant Activation ◽  
Defect Creation ◽  
Si Films ◽  
High Level

ABSTRACTDefect creation mechanisms during solid phase crystallization (SPC) of Si thin films were investigated with PECVD amorphous precursor samples produced with various deposition temperatures and thicknesses. These precursor films were implanted with dopant and then crystallized to obtain both SPC and dopant activation. The doping efficiency was found to decrease with the tensile stress level as measured by Raman shift. The stress shows a decrease as the precursor deposition temperature and thickness are lowered. Furthermore, a lower level of stress is induced by rapid thermal annealing when the annealing temperature is high enough to soften the glass substrate on which the films were deposited. We show that by control of stress during the SPC step, intragrain defect density can be lowered and electronic quality of the resulting polycrystalline Si films can be improved. Based on these observations, we propose the following tentative model to explain the defect creation: during SPC, tensile stress evolution is considered to result from the volumetric contraction of Si film when it transforms from the amorphous to crystalline phase. This contraction is retarded by the substrate, which imposes a tensile stress on the film. A high level of stress leads to formation of structural defects inside the grains of the resulting polycrystalline material. These defects trap carriers or complex with the dopant reducing doping efficiency.

Solid-Phase Crystallization of a-Si:H by RTA

2010 ◽  
Vol 44-47 ◽  
pp. 4151-4153 ◽  
Author(s):  
Rui Min Jin ◽  
Ding Zhen Li ◽  
Lan Li Chen ◽  
Xiang Ju Han ◽  
Jing Xiao Lu
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Amorphous Silicon ◽  
Glass Substrate ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Solid Phase Crystallization ◽  
X Ray ◽  
Average Grain Size ◽  
Electronic Microscope

Amorphous silicon films prepared by PECVD on glass substrate has been crystallized by rapid thermal annealing (RTA) at the same temperature for different time. From X-ray diffraction (XRD) and scanning electronic microscope (SEM), it is found that the grain size is biggest crystallized at 720°C for 8 min, an average grain size of 28nm or so is obtained. The thin film is smoothly and perfect structure.

scholarly journals Study of Phase Formation Processes in Li2ZrO3 Ceramics Obtained by Mechanochemical Synthesis

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Maxim V. Zdorovets ◽  
Artem L. Kozlovskiy ◽  
Baurzhan Abyshev ◽  
Talgat A. Yensepbayev ◽  
Rizahan U. Uzbekgaliyev ◽  
...  
Keyword(s):  
Phase Formation ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Image Data ◽  
Formation Processes ◽  
Ceramic Structure ◽  
Current Voltage ◽  
Average Grain Size ◽  
Temperature Dependences

The article is dedicated to the study of the phase formation processes in Li2ZrO3 ceramics obtained by the method of solid phase synthesis. Interest in these types of ceramics is due to their great potential for use as blanket materials in thermonuclear reactors, as well as being one of the candidates for tritium breeder materials. Analysis of the morphological features of the synthesized ceramics depending on the annealing temperature showed that the average grain size is 90–110 nm; meanwhile the degree of homogeneity is more than 90% according to electronic image data processing results. The temperature dependences of changes in the structural and conducting characteristics, as well as the phase transformation dynamics, have been established. It has been determined that a change in the phase composition by displacing the impurity LiO and ZrO2 phases results in the compaction of ceramics, as well as a decrease in their porosity. These structural changes are due to the displacement of LiO and ZrO2 impurity phases from the ceramic structure and their transformation into the Li2ZrO3 phase. During research, the following phase transformations that directly depend on the annealing temperature were established: LiO/ZrO2/Li2ZrO3 → LiO/Li2ZrO3 → Li2ZrO3. During analysis of the obtained current-voltage characteristics, depending on the annealing temperature, it was discovered that the formation of the Li2ZrO3 ordered phase in the structure results in a rise in resistance by three orders of magnitude, which indicates the dielectric nature of the ceramics.

scholarly journals Solid-phase crystallization under continuous heating: Kinetic and microstructure scaling laws

2008 ◽  
Vol 23 (2) ◽  
pp. 418-426 ◽  
Author(s):  
J. Farjas ◽  
P. Roura
Keyword(s):  
Grain Size ◽  
Kinetic Parameters ◽  
Scaling Laws ◽  
Solid Phase ◽  
Scaling Law ◽  
Continuous Heating ◽  
Dimensionless Time ◽  
Solid Phase Crystallization ◽  
Average Grain Size ◽  
Length Scaling

The kinetics and microstructure of solid-phase crystallization under continuous heating conditions and random distribution of nuclei are analyzed. An Arrhenius temperature dependence is assumed for both nucleation and growth rates. Under these circumstances, the system has a scaling law such that the behavior of the scaled system is independent of the heating rate. Hence, the kinetics and microstructure obtained at different heating rates differ only in time and length scaling factors. Concerning the kinetics, it is shown that the extended volume evolves with time according to αex = [exp(κCt′)]m+1, where t′ is the dimensionless time. This scaled solution not only represents a significant simplification of the system description, it also provides new tools for its analysis. For instance, it has been possible to find an analytical dependence of the final average grain size on kinetic parameters. Concerning the microstructure, the existence of a length scaling factor has allowed the grain-size distribution to be numerically calculated as a function of the kinetic parameters.

Large-Grain Polysilicon Films with Low Intragranular Defect Density by Low-Temperature Solid-Phase Crystallization

2002 ◽  
Vol 715 ◽  
Author(s):  
Xiang-Zheng Bo ◽  
Nan Yao ◽  
J. C. Sturm
Keyword(s):  
Grain Size ◽  
Defect Density ◽  
Solid Phase ◽  
Solid Phase Crystallization ◽  
Transmission Electron ◽  
Cantilever Structure ◽  
Order Of Magnitude ◽  
Polysilicon Films ◽  
Silicon Interface ◽  
Atomic Rearrangement

AbstractSolid phase crystallization (SPC) of a-Si: H at 600°C was investigated by transmission electron microscopy (TEM) and Raman spectroscopy in a cantilever structure, where the underlying SiO2 was removed prior to the crystallization. The absence of the underlying oxide leads to both a higher grain size and a lower intragranular defect density. The grain size increases from 0.6 μm in regions with the underlying oxide to 3.0 μm without the underlying oxide, and the intragranular defect density decreases one order of magnitude from ∼ 1011 cm-2 to ∼ 1010 cm-2. The improvements in material quality without the lower a-Si/SiO2 interface are thought to be due to a lower nucleation rate and a lower tensile stress with an easier silicon atomic rearrangement at the lower silicon interface.

Solid Phase Crystallization (SPC) Behavior of Amorphous Si Bilayer Films with Different Concentration of Oxygen: Surface vs. Interface-nucleation

2000 ◽  
Vol 621 ◽  
Author(s):  
Myung-Kwan Ryu ◽  
Jang-Yeon Kwon ◽  
Ki-Bum Kim
Keyword(s):  
Oxygen Concentration ◽  
Solid Phase ◽  
Film Surface ◽  
Single Layer ◽  
Bilayer Structure ◽  
Solid Phase Crystallization ◽  
Bilayer Films ◽  
Surface Nucleation ◽  
Amorphous Si ◽  
Oxygen Surface

ABSTRACTSolid-phase crystallization (SPC) behavior of a-Si film [a-Si(II)] in which oxygen concentration (CO) is higher at the a-Si/SiO2 interface (CO=5×1021/cm3) than at the film surface (CO=3×1020/cm3) has been investigated. The results were also compared with that of a-Si single layer [a- Si(I), 600 Å] with CO=3×1020/cm3. It has been found that the interface-nucleation was suppressed in the a-Si(II) and the surface-nucleation occurred to make a poly-Si/a-Si (300 Å/300Å) bilayer structure. Many equiaxial grains with sizes of 1∼2 [.proportional]m were formed in the surface- nucleated poly-Si layer. Compared with the results of conventional SPC poly-Si (600 Åthick) in which elliptical grains with sizes of 0.5∼1 [.proportional]m were formed by the interface (a-Si/SiO2)- nucleation, we concluded that the poly-Si/a-Si bilayer scheme is a method to improve the microstructure of SPC poly-Si film.

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