Monitoring of crystallization and the effect of the deposition rate, hydrogen content and annealing process on the crystallization of hot wire chemical vapor deposited hydrogenated amorphous silicon (a-Si:H) films
TL;DR: The crystallization behavior of the a-Si:H films grown by hot wire chemical vapor deposition has been studied using X-ray diffraction (XRD) and reflectance spectroscopy.
About: This article is published in Thin Solid Films.The article was published on 2008-07-31. It has received 21 citations till now. The article focuses on the topics: Carbon film & Combustion chemical vapor deposition.
Citations
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TL;DR: In this paper, the optical properties and crystallinity of hydrogenated nanocrystalline silicon (nc-Si:H) thin films prepared in a home-built radio-frequency (rf) plasma enhanced chemical vapour deposition (PECVD) system have been studied.
44 citations
TL;DR: In this paper, the effect of the microstructure of remote plasma-deposited amorphous silicon films on the grain size development in polycrystalline silicon upon solid-phase crystallization is reported.
Abstract: In this paper the effect of the microstructure of remote plasma-deposited amorphous silicon films on the grain size development in polycrystalline silicon upon solid-phase crystallization is reported. The hydrogenated amorphous silicon films are deposited at different microstructure parameter values R* (which represents the distribution of SiHx bonds in amorphous silicon), at constant hydrogen content. Amorphous silicon films undergo a phase transformation during solid-phase crystallization and the process results in fully (poly-)crystallized films. An increase in amorphous film structural disorder (i.e., an increase in R*), leads to the development of larger grain sizes (in the range of 700-1100 nm). When the microstructure parameter is reduced, the grain size ranges between 100 and 450 nm. These results point to the microstructure parameter having a key role in controlling the grain size of the polycrystalline silicon films and thus the performance of polycrystalline silicon solar cells.
23 citations
TL;DR: In this paper, the effects of rf power on the interlayer elemental profiling, structural and optical properties of the films were investigated by Auger electron spectroscopy, Fourier transform infrared (FTI), Raman scattering and X-ray diffraction.
Abstract: Hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited on c-Si and quartz substrates by layer-by-layer (LBL) technique using radio-frequency plasma enhanced chemical vapour deposition system. The effects of rf power on the interlayer elemental profiling, structural and optical properties of the films were investigated by Auger electron spectroscopy, Fourier transform infrared spectroscopy, Raman scattering spectroscopy, X-ray diffraction and optical transmission and reflection spectroscopy. The results revealed that the LBL deposition leads to a formation of different ranges of crystallite sizes of nc-Si corresponds 3–6 and 8–26 nm respectively. LBL deposition also demonstrated a capability to increase the crystalline volume fraction of nc-Si up to 65.3 % with the crystallite size in between 5 and 6 nm, at the rf power in between 80 and 100 W. However, the crystalline volume fraction decreased for the rf power above 100 W due to the growth of nc-Si was suppressed by the formation of SiO2. In addition, the onset of crystallization of the films deposited on c-Si and quartz substrates are different with increase in the rf power. The effects of rf power on the growth of nc-Si, and the hydrogen content, structural disorder, crystallite size of nc-Si and oxygen diffusion into the LBL layer with the change of optical energy gap under the variation of rf power are also discussed.
21 citations
TL;DR: In this article, Raman scattering analysis is used to study the residual stress in metal-induced crystallized amorphous silicon thin film, and the influence of the crystallization parameters on thin film properties is investigated as a function of annealing temperature, annesaling time, and nickel top-seed-layer thickness.
19 citations
TL;DR: In this paper, the self-rectifying resistive switching (RS) behavior is demonstrated in Ti/ZrN/Pt/p-Si resistive random access memory (RRAM) devices.
Abstract: In this Letter, the self-rectifying resistive switching (RS) behavior is demonstrated in Ti/ZrN/Pt/p-Si resistive random access memory (RRAM) devices. Compared to an RS characteristic of the conventional Ti/ZrN/Pt structures, the memory cell with a p-Si bottom layer shows a larger current ratio. However, a current-limited region is also more clearly obtained in a low voltage region, which can result in one diode-type RRAM with self-selecting properties. Consequently, these results infer that the proposed ZrN-based RRAM cells with a Pt/p-Si selector warrant the realization of the self-selecting RRAM cell without any additional peripheral elements to suppress a disturbance in the reading operation.
16 citations
References
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TL;DR: In this paper, it was shown that hydrogenated amorphous silicon containing as little as 1/10 the bonded H observed in device-quality glow discharge films have been deposited by thermal decomposition of silane on a heated filament.
Abstract: Device‐quality hydrogenated amorphous silicon containing as little as 1/10 the bonded H observed in device‐quality glow discharge films have been deposited by thermal decomposition of silane on a heated filament. These low H content films show an Urbach edge width of 50 mV and a spin density of ∼1/100 as large as that of glow discharge films containing comparable amounts of H. High substrate temperatures, deposition in a high flux of atomic H, and lack of energetic particle bombardment are suggested as reasons for this behavior.
464 citations
TL;DR: In this paper, the average grain size of the crystallized amorphous silicon films depends on the annealing temperature and the deposition conditions, and the final grain size is also influenced by the annaling temperature with the largest grain size obtained at low-annealing temperatures.
Abstract: The crystallization of undoped amorphous silicon films deposited by low‐pressure chemical vapor deposition in the temperature range 580–530 °C and annealed from 550 to 950 °C has been studied by transmission electron microscopy. The average grain size of the crystallized films depends on the annealing temperature and the deposition conditions. The nucleation rate of new grains during annealing decreases as the deposition temperature decreases from 580 to 545 °C and/or when the deposition rate increases. The final grain size is also influenced by the annealing temperature with the largest grain size obtained at low annealing temperatures. A simple model is described which explains the dependence of grain size on the annealing temperature. An average grain size of 500 nm has been obtained in a 200‐nm film deposited at 545 °C and annealed at 550 °C.
327 citations
TL;DR: In this article, the authors used x-ray diffraction, TEM, SEM, Raman and elastic light scattering, optical absorption and reflection, and other techniques in order to obtain information on the grain size, structure, structural perfection, and surface roughness.
Abstract: Undoped LPCVD silicon films have been deposited at five temperatures between 560° and 620°C. The films were characterized as grown and after thermal annealing at 900°, 950°, and 1000°C. We used x‐ray diffraction, TEM, SEM, Raman and elastic light scattering, optical absorption and reflection, and other techniques in order to obtain information on the grain size, structure, structural perfection, and surface roughness. We found that polysilicon films of good structural perfection, low strain, and small surface roughness are obtained when the films are deposited in the amorphous phase and subsequently crystallized at 900°–1000°C. Such films are superior in all investigated material aspects to films grown in the crystalline phase.
224 citations
TL;DR: In this article, the structural properties of amorphous and micro-crystalline silicon films were investigated using Raman spectroscopy, and it was found that a strong relationship exists between the structural order of the silicon matrix and the deposition temperature and deposition rate, and that optimization of the asdeposited silicon microstructure is possible by selecting deposition conditions yielding peak-ratio values in the vicinity of 0.53.
Abstract: In this work we used Raman spectroscopy to investigate the structural characteristics of as‐deposited amorphous and micro‐crystalline silicon films. For amorphous silicon films, the order (or disorder) of the silicon network was quantified using properties of the Raman spectra that were related to key deposition conditions. We found that a strong relationship exists between the structural order of the silicon matrix and the deposition temperature and deposition rate. A quantitative model was proposed relating the intensity ratio of transverse optical phonon peak to longitudinal optical phonon peak to the surface diffusion length, a parameter that was calculated from available data. It was found that optimization of the as‐deposited silicon microstructure is possible by selecting deposition conditions yielding peak–ratio values in the vicinity of 0.53. For as‐deposited micro‐crystalline silicon films, Raman spectroscopy was used to estimate the initial crystalline fraction of the film and monitor the cryst...
217 citations
IBM1
TL;DR: In this paper, the authors investigated the kinetics and morphology in crystallization of unsupported amorphous silicon films by hot stage transmission electron microscopy and obtained activation energies of 470 kJ/mol for nucleation and 280 kJ /mol for growth.
Abstract: Kinetics and morphology in crystallization of unsupported amorphous silicon films are investigated by hot stage transmission electron microscopy. Crystallization occurs by thermally activated nucleation and growth processes; activation energies of 470 kJ/mol for nucleation and 280 kJ/mol for growth are obtained. Nucleation rates are observed to increase with annealing time, whereas the growth rate depends on the annealing temperature and the crystallographic growth direction.
Kinetik und Morphologie der Kristallisation amorpher Silizium-Schichten wird elektronenmikroskopisch untersucht. Die Kristallisation erfolgt uber thermisch aktivierte Keimbildung und Wachstum, wobei die Aktivierungsenergie mit 470 kJ/Mol fur die Keimbildung und 280 kJ/Mol fur das Wachstum bestimmt werden. Die Keimbildungsrate nimmt wahrend isothermer Temperung zu; die Wachstumsgeschwindigkeit hangt dagegen nur von der Temperungstemperatur und der kristallographischen Wachstumsrichtung ab.
158 citations