An AFM Study of The Effect of Growth Method and Conditions on The Microstructure of A-Si:H

1997 ◽  
Vol 467 ◽  
Author(s):  
Daewon Kwon ◽  
J. David Cohen ◽  
Ricardo Garcia
Keyword(s):  
Grain Size ◽  
Particle Production ◽  
Chemical Vapor ◽  
Gas Mixtures ◽  
Micro Structure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Growth Method ◽  
Gas Dilution ◽  
Substrate Temperatures

ABSTRACTWe utilized atomic force microscopy (AFM) to investigate the microstructure at the surface of thick (>4000 Å) hydrogenated amorphous silicon films. The films were prepared by standard glow discharge (GD) as well as hot wire chemical vapor deposition (HWCVD) techniques. We studied a series of films with substrate temperatures ranging between 200 °C and 400 °C. We also studied the effects of various gas mixtures at fixed growth temperature on the observed microstructure. We found that the average feature grain size in the micro structure varied between 40 nm and 90 nm as the substrate temperature was changed and also as the different gas mixtures were employed during growth. The grain size decreased with increasing substrate temperatures for the films grown from 100 % silane independent of whether the growth method were GD or HWCVD. Gas dilution with argon or hydrogen also resulted in a size reduction, as did PH3 doping at dilute levels. These results rule out the possibilities that the observed features arise from particle production in the reactor chamber itself. The relation of the observed micro structure to the electronic properties of a-Si:H is discussed.

Ni Removal from Si Wafers by Low-Pressure UV-Chlorine Cleaning

1997 ◽  
Vol 477 ◽  
Author(s):  
C. H. Courtney ◽  
H. H. Lamb
Keyword(s):  
Physical Vapor Deposition ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Surface Concentration ◽  
Low Pressure ◽  
Force Microscopy ◽  
Etching Mechanism ◽  
Photochemical Etching ◽  
Atomic Force ◽  
Substrate Temperatures

ABSTRACTNi removal from Si wafers by low-pressure UV/Cl2 chemical vapor cleaning (CVC) was investigated at substrate temperatures of 150–200°C. Sub-monolayer Ni coverages were applied to Si(100) by ultrahigh-vacuum physical vapor deposition (UHV-PVD). The Ni surface concentration was reduced to the Auger electron spectroscopy (AES) detection limit by a 2-min UV/Cl2 exposure at 300 mTorr and 200°C. AES depth profiling revealed that Ni was not contained within nor buried beneath the chlorosilyl layer formed by UV/Cl2 CVC. In contrast, Ni was not removed under similar conditions from Si surfaces covered by a thin UV/air oxide layer. These results indicate that Ni removal from Si occurs by a photochemical etching mechanism and not by direct volatilization of NiCl2. Atomic force microscopy (AFM) of Si surfaces after UV/Cl2 CVC indicated that Si etching was limited ˜20 å and that the surface was smooth (RMS roughness = 1.6 å).

Fabrication of AFM Single-Walled Carbon Nanotube Tips

2007 ◽  
Author(s):  
Rui Wang ◽  
Hua-Ming Xu ◽  
Qian-Ming Gong ◽  
Ji Liang
Keyword(s):  
Atomic Force Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Mechanical Method ◽  
Force Microscopy ◽  
Atomic Force ◽  
Growth Method ◽  
Direct Growth ◽  
Silicon Probes

Probe is a key part of atomic force microscopy (AFM) and the curvature radius of its tip limits the lateral resolution. Furthermore, as an expendable, its life has a direct effect on operation cost. Single-walled carbon nanotubes (SWNTs) are ideal materials for the probe tips used in atomic force microscopy (AFM), since they have intrinsically small diameters, high aspect ratios and unique wearability. Herein, the fabrication of AFM SWNT tips is systemically investigated, including mechanical method and direct growth method. In the former, substrates with isolated SWNTs are first prepared by chemical vapor deposition and then scanned with conventional silicon probes under AFM. During scanning, SWNTs can be picked up from substrates and attached to the pyramid of silicon probes via attractive Van del Waals forces. Preparation of substrates is decisive to this method, since only the SWNTs disengaged from surface are possible to pick up. Different substrates have been compared and the results show that the substrates full of gaps are prior to the planar ones. SWNTs are suspended across gaps and suitable to the following assembly. The mechanical method is easily implemented and can produce AFM SWNT tips one by one, while the direct growth method is promising to manufacture them in a large scale, in spite of more difficulty. In the latter, catalyst for the growth of SWNTs is directly placed on individual commercial probes or pyramid arrays. Through chemical vapor deposition, grown SWNTs protrude from the original tips and create new ones. Due to the random orientation of SWNT growth, the yield of successful SWNT tips is generally low for the direct growth method. In this article, Electric filed is used to direct the growth orientation of SWNTs during chemical vapor deposition. Both electrodes are located in the furnace to apply a static electric field along the pyramid axis during growth. The intensity can be varied from 0.1V/um to IV/um, and the direction is towards the surface of wafers. The growth of SWNTs is oriented by electric field and the yield of SWNT tips is raised. The AFM SWNT tips derived from the above two methods have been utilized to image Au layers in the tapping mode. Compared with conventional silicon probes, SWNT tips are longer lasting to keep a high resolution.

Structural Evolution of Nanocrystalline Germanium Thin Films with Film Thickness and Substrate Temperature

2003 ◽  
Vol 762 ◽  
Author(s):  
William B. Jordan ◽  
Eric D. Carlson ◽  
Todd R. Johnson ◽  
Sigurd Wagner
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Film Thickness ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Structural Evolution ◽  
Chemical Vapor ◽  
Force Microscopy ◽  
Atomic Force

AbstractThe structure of germanium thin films prepared on glass by plasma enhanced chemical vapor deposition was characterized by Raman spectroscopy, atomic force microscopy (AFM) and field emission scanning electron microscopy (SEM). Crystallinity, surface roughness, and grain size were measured as functions of film thickness and deposition temperature. Grain nucleation was apparent for films as thin as 10 nm. Over the thickness range studied, grain size increased with film thickness, whereas average surface roughness started to increase with film thickness, but then remained fairly constant at approximately 1 nm for a film thickness greater than 25 nm.

Direct Growth of Graphene on SiO2 by Using Ga-Ni Flux

2013 ◽  
Vol 477-478 ◽  
pp. 1242-1245
Author(s):  
Qiang Yu ◽  
Jing Cun Zhang ◽  
Bing Cao ◽  
Shun Yu He ◽  
Chin Hua Wang ◽  
...  
Keyword(s):  
Sacrificial Layer ◽  
Carbon Film ◽  
Graphene Film ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Force Microscopy ◽  
Dielectric Substrates ◽  
Atomic Force ◽  
Growth Method ◽  
Direct Growth

A new growth method of graphene directly on the bare dielectric substrates by CVD (Chemical Vapor Deposition) method with Ga-Ni flux as sacrificial layer is reported in this work. Ga-Ni flux acts as not only a container to store carbon atoms which are dissolved from amourphous carbon film when heated, but also as a catalyst to promote the formation of graphene when cooled. In the process of growth, the Ga-Ni flux dewets and evaporates during the rearrangement of carbon atoms, resulting in graphene synthesized directly on the bare dielectric substrates. Scanning Raman Mapping and Spectroscopy, Scanning Electron Microscopy, and Atomic Force Microscopy were adopted to characterize the graphene film.

Effect of Gas Dilution Ratios and Substrate Temperature on the Structural Transition of a-Si/μc-Si Thin-Film Solar Cell Using PECVD

2018 ◽  
Vol 786 ◽  
pp. 373-383
Author(s):  
Heba R. Abd El-Aaty ◽  
Osama Tobail ◽  
Madiha A. Shoeib ◽  
Iman El-Mahallawi
Keyword(s):  
Thin Film ◽  
Substrate Temperature ◽  
Indium Tin Oxide ◽  
Structural Transition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ito Glass ◽  
Gas Dilution

Thin films of mixed amorphous/ microcrystalline-phases have been researched during the last decade, for manufacturing silicon solar cells. In this work the Plasma Enhanced Chemical Vapor Deposition PECVD process parameters; namely dilution ratios and substrate temperature, were controlled to build i-layer at low dilution ratios with moderate substrate temperatures. In this work an intrinsic layer was deposited on Indium Tin Oxide ITO glass by PECVD technique, with different dilution ratios of silane in hydrogen to study the transition from amorphous to microcrystalline phase. The Si:H thin film was evaluated by field emission scanning electron microscopy, x-ray diffraction and atomic force microscopy. The structural transition between a-Si:H to μc-Si:H achieved at dilution ratio 13.3 and substrate temperature 250°C with surface roughness 22.5 nm.

scholarly journals Influence of Growth Temperature of the Nucleation Layer on the Growth of InP on Si (001)

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 823
Author(s):  
Shizheng Yang ◽  
Hongliang Lv ◽  
Likun Ai ◽  
Fangkun Tian ◽  
Silu Yan ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Wafer Level ◽  
X Ray Diffraction ◽  
Nucleation Layer ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Growth Method ◽  
Step Growth ◽  
Microscopy Images

InP layers grown on Si (001) were achieved by the two-step growth method using gas source molecular beam epitaxy. The effects of growth temperature of nucleation layer on InP/Si epitaxial growth were investigated systematically. Cross-section morphology, surface morphology and crystal quality were characterized by scanning electron microscope images, atomic force microscopy images, high-resolution X-ray diffraction (XRD), rocking curves and reciprocal space maps. The InP/Si interface and surface became smoother and the XRD peak intensity was stronger with the nucleation layer grown at 350 °C. The Results show that the growth temperature of InP nucleation layer can significantly affect the growth process of InP film, and the optimal temperature of InP nucleation layer is required to realize a high-quality wafer-level InP layers on Si (001).

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Effectiveness and Reliability of Metal Diffusion Barriers for Copper Interconnects

1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Diffusion Barriers ◽  
Copper Interconnects ◽  
Time To Failure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.

scholarly journals Influence of the growth parameters of TiO2 thin films deposited by the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Deposition Parameters

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.

scholarly journals Photothermal Deflection Spectroscopy Study of Nanocrystalline Si (nc-Si) Thin Films Deposited on Porous Aluminum with PECVD

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
S. Ktifa ◽  
M. Ghrib ◽  
F. Saadallah ◽  
H. Ezzaouia ◽  
N. Yacoubi
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Porous Aluminum ◽  
Force Microscopy ◽  
Photothermal Deflection Spectroscopy ◽  
Atomic Force ◽  
Photothermal Deflection ◽  
Morphology Characterization

We have studied the optical properties of nanocrystalline silicon (nc-Si) film deposited by plasma enhancement chemical vapor deposition (PECVD) on porous aluminum structure using, respectively, the Photothermal Deflection Spectroscopy (PDS) and Photoluminescence (PL). The aim of this work is to investigate the influence of anodisation current on the optical properties of the porous aluminum silicon layers (PASL). The morphology characterization studied by atomic force microscopy (AFM) technique has shown that the grain size of (nc-Si) increases with the anodisation current. However, a band gap shift of the energy gap was observed.

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