TEM Analysis of Psuedo-Amorphous and Polycrystalline Silicon Thin Films

1972 ◽  
Vol 30 ◽  
pp. 508-509
Author(s):  
Ronald M. Anderson
Keyword(s):  
Integrated Circuits ◽  
Polycrystalline Silicon ◽  
Electronics Industry ◽  
Tem Analysis ◽  
Silicon Thin Films ◽  
Pyrolytic Decomposition ◽  
Diffuse Ring ◽  
Heat Treated ◽  
Thin Polycrystalline ◽  
Si Films

Thin polycrystalline Si films are used in certain aspects of the fabrication of integrated circuits in the electronics industry. To date, analysis of Si films has been confined to thick films (10-50μ) deposited and/or heat-treated at temperatures over 800°C. The pyrolytic decomposition of silane gas in nitrogen or hydrogen carriers is the most common deposition technique in the industry. In the present work, thin Si films, e-beam evaporated at 300°C onto SiO2 and Si3N4 substrates and subsequently heat-treated at temperatures from 450°C to 1040°C are compared to films deposited onto SiO2, Si3N4 and Al2O3 by the pyrolytic decomposition of silane gas at temperatures from 500°C to 900°C with no further heat-treatment.The evaporated films are psuedo-amorphous as-deposited and remain so after subsequent heat-treatments up to 600°C for one hour. A psuedo-amorphous diffraction pattern is seen in Fig.1; the first diffuse ring occurs at the Si (111) radius and the second broad diffuse ring spans the radii of the Si (220) and (311) reflections.

scholarly journals Fabrication of Large-Grain Thick Polycrystalline Silicon Thin Films via Aluminum-Induced Crystallization for Application in Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Hsiao-Yeh Chu ◽  
Min-Hang Weng ◽  
Chen Lin
Keyword(s):  
Solar Cells ◽  
Polycrystalline Silicon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Second Stage ◽  
Silicon Thin Films ◽  
Si Films ◽  
Two Stages ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

The fabrication of large-grain 1.25 μm thick polycrystalline silicon (poly-Si) films via two-stage aluminum-induced crystallization (AIC) for application in thin-film solar cells is reported. The induced 250 nm thick poly-Si film in the first stage is used as the seed layer for the crystallization of a 1 μm thick amorphous silicon (a-Si) film in the second stage. The annealing temperatures in the two stages are both 500°C. The effect of annealing time (15, 30, 60, and 120 minutes) in the second stage on the crystallization of a-Si film is investigated using X-ray diffraction (XRD), scanning electron microscopy, and Raman spectroscopy. XRD and Raman results confirm that the induced poly-Si films are induced by the proposed process.

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.

Fast Deposition of Polycrystalline Silicon Films by Hot-Wire CVD

1995 ◽  
Vol 377 ◽  
Author(s):  
A. R. Middya ◽  
A. Lloret ◽  
J. Perrin ◽  
J. Huc ◽  
J. L. Moncel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Polycrystalline Silicon ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hot Wire ◽  
Crystalline Orientation ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTPolycrystalline silicon thin films have been deposited at fast growth rates (50 Å/s) by hotwire chemical vapour deposition (HW-CVD) from SiH4/H2 gas mixtures at low substrate temperature (400–500°C). The surface morphology of these films consists of 0.5 – 2.0μm dendritic grains as seen by electron microscopy. The films have a columnar morphology with grains starting from the substrate either on glass or c-Si. Even the 150 nm thick initial layer is polycrystalline. The preferential crystalline orientation of the poly-Si film is apparently not governed by the radiative source but strongly depends on the type and orientation of the substrate. A strong hydrogen dilution (>90%) of silane is essential to obtain poly-Si films with optimal crystalline structure.

A Study on the Metal Induced Lateral Crystallization Behavior of Amorphous Silicon Thin Films

1996 ◽  
Vol 441 ◽  
Author(s):  
Byung-Il Lee ◽  
Kwang-Ho Kim ◽  
Won-Cheol Jeong ◽  
Pyung-Su Ahn ◽  
Jin-Wook Shin ◽  
...  
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
External Stress ◽  
Tem Analysis ◽  
Silicon Thin Films ◽  
Amorphous Si ◽  
Lateral Crystallization ◽  
Si Films

AbstractBasic mechanisms for both Ni- and Pd-metal induced lateral crystallization (MILC) are investigated. For both cases, tiny silicides were formed under the metal deposited area, and propagated toward amorphous Si films leaving crystallized Si behind at temperatures as low as 500 °C. Ni-MILC was influenced by Pd such that the lateral crystallization rate was enhanced, and the temperature for the lateral crystallization was lowered to 450 °C. Through TEM analysis and external stress experiments, it was found that the enhancement of the lateral crystallization rate was closely related to the compressive stress generated by the formation of nearby Pd2Si.

Stress-Corrosion Cracking and Blistering of Thin Polycrystalline Silicon Films in Hydrofluoric Acid

1993 ◽  
Vol 308 ◽  
Author(s):  
D.J. Monk ◽  
P. Krulevitch ◽  
R.T. Howe ◽  
G.C. Johnson
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Hydrofluoric Acid ◽  
Polycrystalline Silicon ◽  
Corrosion Cracking ◽  
Foreign Particle ◽  
Phosphosilicate Glass ◽  
Thin Polycrystalline ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTThin (0.1 μm) LPCVD polycrystalline silicon (poly-Si) films are shown to exhibit permeability and suffer structural degradation when exposed to concentrated hydrofluoric acid. Analysis by TEM and SEM reveals two attack mechanisms. (1) Poly-Si films deposited onto phosphosilicate glass (PSG) at 605ºC exhibit tensile residual stress and degrade immediately upon exposure to HF, a phenomenon which we attribute to stress-corrosion cracking. Phosphorus from the PSG layer enters the poly-Si during the deposition, resulting in a microstructural gradient which contributes to the cracking mechanism. (2) As-deposited tensile poly-Si films on phosphorus-free LPCVD SiO2 (LTO) and annealed films on LTO and PSG blister at different rates in HF due to penetration at foreign particle inclusion sites and other film defects. Unannealed compressive films deposited at 650ºC onto PSG do not show any evidence of attack.

Hexagonal phase in tensile low-pressure CVD poly-Si film

1991 ◽  
Vol 49 ◽  
pp. 812-813
Author(s):  
Tai D. Nguyen
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
High Pressure ◽  
Integrated Circuits ◽  
Polycrystalline Silicon ◽  
Hexagonal Phase ◽  
Grain Morphology ◽  
Compressive Buckling ◽  
Columnar Grain ◽  
Si Films

Polycrystalline silicon (poly-Si) films have found many applications in integrated circuits, and in actuators and sensors. Important considerations in the processing of these devices are structural stability and repeatable mechanical properties of the films. The texture and stress state of the films depend strongly on the microstructures and morphology of the films. Tensile films, which are preferred to compressive films in devices whose lateral dimensions of clamped structures are not to be restricted by compressive buckling, are characterized by equiaxial grain morphology, while compressive films are characterized by columnar grain growth during deposition.A diamond hexagonal (d.h.) Si structure with lattice parameters of a = 3.8Å and c = 6.28Å was first reported in 1963. More recently, transformation from the diamond cubic (d.c.) Si to the hexagonal phase has been observed in Si under hydrostatic pressure at temperatures between 350 C and 700 C, in heavily ion-implanted silicon, and in as-grown, implanted, and annealed CVD Si thin films, in addition to the known high pressure Si phases.

Polycrystalline Silicon Thin Films For Microelectronic Applications

2000 ◽  
Vol 609 ◽  
Author(s):  
Elena A. Guliants ◽  
Young J. Song ◽  
Wayne A. Anderson
Keyword(s):  
Thin Films ◽  
Polycrystalline Silicon ◽  
Carrier Lifetime ◽  
Diffusion Length ◽  
Schottky Diodes ◽  
Reverse Current ◽  
Silicon Thin Films ◽  
Microelectronic Devices ◽  
Si Films ◽  
Film Interface

ABSTRACTPolycrystalline silicon thin films with a thickness of 0.5-2μm were grown on 25nm thick Ni prelayers by d.c. magnetron sputtering from a Si target. In contrast to the conventional sputtering, the use of a thin Ni film allows the production of high crystallinity silicon at a temperature of 475°C and higher. The Ni disilicide grains formed at the Ni - growing Si film interface provide sufficient sites for the epitaxial growth of Si. The Si films with resistivity of 102-103Ω-cm possess a carrier lifetime of up to 11μs and a diffusion length of up to 3.4 μm, which makes them applicable to various microelectronic devices. As an example, Schottky diodes fabricated on 0.5μm thick Si films exhibit a forward-to-reverse current ratio of 107. The technique is easily implemented on a variety of substrates.

Interface morphology of thermal oxide grown on polycrystalline silicon by different processes

1992 ◽  
Vol 50 (2) ◽  
pp. 1396-1397
Author(s):  
H. Yen ◽  
E. P. Kvam ◽  
R. Bashir ◽  
S. Venkatesan ◽  
G. W. Neudeck
Keyword(s):  
Integrated Circuits ◽  
Polycrystalline Silicon ◽  
Silicon Films ◽  
Interface Morphology ◽  
Oxide Interface ◽  
Poly Silicon ◽  
Thermal Oxide ◽  
Grain Orientations ◽  
Polycrystalline Silicon Films ◽  
P Type

Polycrystalline silicon, when highly doped, is commonly used in microelectronics applications such as gates and interconnects. The packing density of integrated circuits can be enhanced by fabricating multilevel polycrystalline silicon films separated by insulating SiO2 layers. It has been found that device performance and electrical properties are strongly affected by the interface morphology between polycrystalline silicon and SiO2. As a thermal oxide layer is grown, the poly silicon is consumed, and there is a volume expansion of the oxide relative to the atomic silicon. Roughness at the poly silicon/thermal oxide interface can be severely deleterious due to stresses induced by the volume change during oxidation. Further, grain orientations and grain boundaries may alter oxidation kinetics, which will also affect roughness, and thus stress.Three groups of polycrystalline silicon films were deposited by LPCVD after growing thermal oxide on p-type wafers. The films were doped with phosphorus or arsenic by three different methods.

Formation of Large, Orientation-Controlled, Nearly Single Crystalline Si Thin Films on SiO2 Using Contact Printing of Rolled and Annealed Nickel Tapes

2003 ◽  
Vol 762 ◽  
Author(s):  
Hwang Huh ◽  
Jung H. Shin
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Resolution ◽  
Amorphous Silicon ◽  
Tem Analysis ◽  
Contact Printing ◽  
Single Crystalline ◽  
High Resolution Tem ◽  
Lateral Crystallization ◽  
Si Films

AbstractAmorphous silicon (a-Si) films prepared on oxidized silicon wafer were crystallized to a highly textured form using contact printing of rolled and annealed nickel tapes. Crystallization was achieved by first annealing the a-Si film in contact with patterned Ni tape at 600°C for 20 min in a flowing forming gas (90 % N2, 10 % H2) environment, then removing the Ni tape and further annealing the a-Si film in vacuum for2hrsat600°C. An array of crystalline regions with diameters of up to 20 μm could be formed. Electron microscopy indicates that the regions are essentially single-crystalline except for the presence of twins and/or type A-B formations, and that all regions have the same orientation in all 3 directions even when separated by more than hundreds of microns. High resolution TEM analysis shows that formation of such orientation-controlled, nearly single crystalline regions is due to formation of nearly single crystalline NiSi2 under the point of contact, which then acts as the template for silicide-induced lateral crystallization. Furthermore, the orientation relationship between Si grains and Ni tape is observed to be Si (110) || Ni (001)

Stresses in thin polycrystalline silicon films

1988 ◽  
Vol 162 ◽  
pp. 365-374 ◽  
Author(s):  
V.M. Koleshko ◽  
V.F. Belitsky ◽  
I.V. Kiryushin
Keyword(s):  
Polycrystalline Silicon ◽  
Silicon Films ◽  
Thin Polycrystalline ◽  
Polycrystalline Silicon Films
Sign in / Sign up

Export Citation Format

Share Document