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).

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.

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.

Homoepitaxial Growth and Characterization of 4H-SiC Epilayers by Low-Pressure Hot-Wall Chemical Vapor Deposition

2006 ◽  
Vol 527-529 ◽  
pp. 191-194 ◽  
Author(s):  
Guo Sheng Sun ◽  
Jin Ning ◽  
Quan Cheng Gong ◽  
Xin Gao ◽  
Lei Wang ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Low Pressure ◽  
Optical Microscope ◽  
Thick Sample ◽  
Force Microscopy ◽  
Homoepitaxial Growth ◽  
Atomic Force ◽  
Blocking Voltage ◽  
Gas System ◽  
Surface Morphologies

Horizontal air-cooled low-pressure hot-wall CVD (LP-HWCVD) system is developed to get high quality 4H-SiC epilayers. Homoepitaxial growth of 4H-SiC on off-oriented Si-face (0001) 4H-SiC substrates purchased from Cree is performed at a typical temperature of 1500°C with a pressure of 40 Torr by using SiH4+C2H4+H2 gas system. The surface morphologies and structural and optical properties of 4H-SiC epilayers are characterized with Nomarski optical microscope, atomic force microscopy (AFM), x-ray diffraction, Raman scattering, and low temperature photoluminescence (LTPL). The background doping of 32 μm-thick sample has been reduced to 2-5×1015 cm-3. The FWHM of the rocking curve is 9-16 arcsec. Intentional N-doped and B-doped 4H-SiC epilayers are obtained by in-situ doping of NH3 and B2H6, respectively. Schottky barrier diodes with reverse blocking voltage of over 1000 V are achieved preliminarily.

Effect of Introducing Free Gaseous Radicals of Trichlorosilane and Ammonia Precursors on Growth and Characteristics of LPCVD a-SiNx Ultra Thin Films

2013 ◽  
Vol 829 ◽  
pp. 401-409
Author(s):  
Armin Salmasi ◽  
Eskandar Keshavarz Alamdari
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Surface Topography ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Arrhenius Behavior ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pressure Chemical ◽  
Rate Ratios

Preparation and characteristics of amorphous silicon nitride (a-SiNx) thin films deposited by low pressure chemical vapor deposition (LPCVD) are investigated. Free gaseous radicals of trichlorosilane (TCS) and ammonia (NH3) are produced by passing each of the precursor gases separately over Pt-Ir/Al2O3 catalyst at the temperature of 600 C. Kinetics studies of the LPCVD are carried out in different total pressures, NH3/TCS flow rate ratios and temperatures. Surface topography, chemical concentrations, growth rate and thickness are studied by Ellipsometry, x-ray photo-electron spectroscopy (XPS), atomic force microscopy (AFM) and auger depth profiling (ADP). Analysis of experiments indicates that at the temperatures between 730 C and 830 C, the growth rate of thin films follows an Arrhenius behavior with activation energy of 166.3 KJ.mol-1. The measured hydrogen contamination in a-SiNx ultra thin films is 1.05 at% which is 17 times lower than the corresponding contamination in the films produced by (PECVD) and 3.4 times lower than the contamination in the LPCVD thin films with silane (SiH4) or dichlorosilane (DCS) and Ammonia. The surface topography of the prepared films is smooth and uniform and the thickness varies between 23 and 101 nanometers.

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.

Copper Diffusion Into Aluminum-Silicon Metallizations by Accelerated Thermal and Electrical Stressing

1996 ◽  
Vol 428 ◽  
Author(s):  
G. O. Ramseyer ◽  
L. H. Walsh ◽  
J. V. Beasock ◽  
H. F. Helbig ◽  
R. C. Lacoe ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Depth Profiling ◽  
Copper Diffusion ◽  
Force Microscopy ◽  
Atomic Force ◽  
Line Widths ◽  
Electromigration Lifetime

AbstractPatterned 930 nm Al(1%-Si) interconnects over 147 nm of Cu were electromigration lifetime tested at 1.0–1.5 × 105 A/cm2 at 250 °C. The morphology of the surfaces of the electromigrated stripes with different line widths and times to failure were characterized by atomic force microscopy, and changes in surface roughness were compared. The diffusion of copper into the electromigrated aluminum stripes was determined by depth profiling using Auger electron spectroscopy. In particular, areas where hillocks formed were examined and compared to areas of median roughness.

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.

Characterization of High Quality, Large-Scale Growth of Monolayer WS2 Domains via Chemical Vapor Deposition Technique

2021 ◽  
Author(s):  
Somayeh Asgary ◽  
Amir Hoshang Ramezani ◽  
Zhaleh Ebrahimi Nejad
Keyword(s):  
Large Scale ◽  
Average Length ◽  
Chemical Vapor ◽  
Growth Time ◽  
High Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Regular Triangle ◽  
Vapor Deposition Technique

Abstract WS2 flakes have been grown successfully on SiO2 substrate via chemical vapor (CVD) deposition method by reduction and sulfurization of WO3 using Ar/ H2 gas and sulfur evaporated from solid sulfur powder. The prepared samples were characterized by optical microscopy (OM), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). Large domain WS2 monolayers are obtained by extending the growth time. The perfect triangular single-crystalline WS2 flakes with an average length of more than 35 µm were achieved. The sharp PL peak (∼1.98 eV) and two distinct Raman peaks (E2g and A1g) with a ∼ 71.5 cm-1 peak split indicating that relatively high quality WS2 crystals with a regular triangle shape can be synthesized. Higher growth time shows larger triangular-shaped of WS2.

DEPOSITION OF WIDE BAND GAP DLC FILMS USING R.F. PECVD AT VERY LOW POWER

2011 ◽  
Vol 25 (29) ◽  
pp. 3941-3949 ◽  
Author(s):  
P. K. BARHAI ◽  
RISHI SHARMA ◽  
B. B. NAYAK
Keyword(s):  
Band Gap ◽  
Chemical Vapor ◽  
Wide Band ◽  
Carbon Films ◽  
Wide Band Gap ◽  
Force Microscopy ◽  
Atomic Force ◽  
Frequency Plasma ◽  
Bending Modes ◽  
Deposited Films

Wide band gap diamond-like carbon films (DLCs) are deposited on silicon (1 0 0) substrates using capacitive coupled radio frequency plasma-enhanced chemical vapor deposition (R.F. PECVD) technique. The deposition of films is carried out at a constant pressure (~5×10-2 mbar ) using acetylene precursor diluted with argon at constant R.F. power of 5 W. Raman spectroscopy of deposited DLC films shows broad G peak near 1550 cm-1 and a weak D peak near 1320 cm1. FTIR plot of DLC films shows a peak near 2900 cm-1 corresponding to C–H stretching mode and peaks below 2000 cm-1 corresponding to C–C modes and C–H bending modes. Maximum hardness of the deposited films is found to be ~15 GPa. Band gap of the DLC films is ~3.5 eV. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) pictures show that the deposited films are amorphous. Deposition mechanism of wide band gap DLC film is explained on the basis of subplantation model.

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