Megasonic Irradiation Induced Chemical Reaction in the Solution for Silicon Wafer Cleaning

1997 ◽  
Vol 477 ◽  
Author(s):  
T. Ohmi ◽  
M. Toda ◽  
M. Katoh ◽  
K. Kawada ◽  
H. Morita
Keyword(s):  
Chemical Reaction ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Coulomb Force ◽  
Oh Radicals ◽  
Ultrapure Water ◽  
Positive Ions ◽  
Cleaning Solution ◽  
Silicon Wafer Cleaning ◽  
Gas Volume

ABSTRACTWe have already proposed chemical vapor free and room temperature wet cleaning (UCT cleaning) for Si substrate surface, instead of conventional RCA cleaning, which consumes very little amount of chemicals and ultrapure water compared to that of RCA cleaning. This new wet cleaning has been developed by scientifically understanding contaminants removal mechanism as follows;(1) Particles can be removed by simultaneously satisfying following two conditions,(a) particles and substructure surface must have same polarity of zeta potential in the cleaning solution to exhibit repulsive electric coulomb force with each other.(b) adhered particles must be lifted off from substrate surface by slight etching to make electric repulsive force greater than van der Waals force,(2) Redox potential of the cleaning solution must be larger than a critical value to enable removal of electrons from adhered metals in order to dissolve them into the cleaning solution as positive ions and to decompose adhered organic molecules to CO2, H2O etc.Megasonic irradiation is very essential in UCT cleaning, particularly to remove particles by lifting them off from substrate surface. In this study, chemical reaction in the cleaning solution induced by megasonic irradiation is mainly discussed. Irradiation of ultrasonic having frequencies higher than a few hundred KHz (Megasonic) to ultrapure water has been confirmed to be able to decompose H2O molecules to H radicals and OH radicals. Decomposition efficiency of H20 molecules is strongly dependent on remaining gas components and their volume in the ultrapure water. When the remaining gas volume is decreased to less than 0.2 ∼0.3ppm, H2O molecules decomposition to H radicals and OH radicals has not been observed. Generated OH radicals have been confirmed to produce H2O2, and NH4+, NO2−, NO3− ions by reacting. with remaining N2 gas. Thus the cleaning capability of the cleaning solutions can be controlled by irradiating megasonic.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Observations on the Growth of YBa2Cu3O7 Thin Films at Very High Laser Fluences

1995 ◽  
Vol 388 ◽  
Author(s):  
Rand R. Biggers. ◽  
M. Grant Norton ◽  
I. Maartense ◽  
T.L. Peterson ◽  
E. K. Moser ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
High Fluences ◽  
Laser Fluences ◽  
High Laser ◽  
High Laser Fluences ◽  
Very High

AbstractThe pulsed-laser deposition (PLD) technique utilizes one of the most energetic beams available to form thin films of the superconducting oxide YBa2Cu3O7 (YBCO). IN this study we examine the growth of YBCO at very high laser fluences (25 to 40 J/cm2); a more typical fluence for PLD would be nearer to 3 J/cm2. the use of high fluences leads to unique film microstructures which, in some cases, appear to be related to the correspondingly higher moveabilities of the adatoms. Films grown on vicinal substrates, using high laser fluences, exhibited well-defined elongated granular morphologies (with excellent transition temperature, Tc, and critical current density, Jc). Films grown on vicinal substrates using off-axis magnetron sputtering, plasma-enhanced metal organic chemical vapor deposition (PE-MOCVD), or PLD at more typical laser fluences showed some similar morphologies, but less well-defined. Under certain growth conditions, using high laser fluences with (001) oriented substrates, the YBCO films can exhibit a mixture of a- and c-axis growth where both crystallographic orientations nucleate on the substrate surface at the same time, and grow in concert. the ratio of a-axis oriented to c-axis oriented grains is strongly affected by the pulse repetition rate of the laser.

Nucleation and selected area deposition of diamond by biased hot filament chemical vapor deposition

1995 ◽  
Vol 10 (2) ◽  
pp. 425-430 ◽  
Author(s):  
W. Zhu ◽  
F.R. Sivazlian ◽  
B.R. Stoner ◽  
J.T. Glass
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Wire Mesh ◽  
Reactor Wall ◽  
Nucleation Density ◽  
Si Substrate ◽  
Diamond Nucleation ◽  
Hot Filament

This paper describes a process for uniformly enhancing the nucleation density of diamond films on silicon (Si) substrates via dc-biased hot filament chemical vapor deposition (HFCVD). The Si substrate was negatively biased and the tungsten (W) filaments were positively biased relative to the grounded stainless steel reactor wall. It was found that by directly applying such a negative bias to the Si substrate in a typical HFCVD process, the enhanced diamond nucleation occurred only along the edges of the Si wafer. This resulted in an extremely nonuniform nucleation pattern. Several modifications were introduced to the design of the substrate holder, including a metal wire-mesh inserted between the filaments and the substrate, in the aim of making the impinging ion flux more uniformly distributed across the substrate surface. With such improved growth system designs, uniform enhancement of diamond nucleation across the substrate surface was realized. In addition, the use of certain metallic wire mesh sizes during biasing also enabled patterned or selective diamond deposition.

Substrate Dependence of Microcrystalline Silicon Growth with SiH4 Diluted by Ar

2014 ◽  
Vol 936 ◽  
pp. 264-268
Author(s):  
Hua Cheng ◽  
Yong Chan Qian ◽  
Jun Xue
Keyword(s):  
Deposition Rate ◽  
Electron Cyclotron Resonance ◽  
Substrate Surface ◽  
Gaseous Mixture ◽  
Film Surface ◽  
Chemical Vapor ◽  
Preferred Orientation ◽  
Initial Stage ◽  
Substrate Dependence ◽  
Si Films

Microcrystalline Si films were deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) using Ar diluted SiH4gaseous mixture. The effects of the substrate on deposition rate, preferred orientation and roughness of the films were investigated. The results show that, the influence of the substrate surface chemical nature on the deposition rate is significant in the initial stage of the growth. And considering the crystallinity and roughness of the films, the substrate is favored in its preferred orientation with a rougher surface. Based on these results, it is confirmed that the combination of diffusion and etching is indispensable to describe the deposition of μc-Si with SiH4diluted by Ar, and the mechanism of μc-Si growth could be controlled by diffusion of Si and etching of the Ar+on the film surface.

Boundary Layer Temperature Profile in Diamond CVD System Using Laser-Induced Fluorescence

1995 ◽  
Vol 416 ◽  
Author(s):  
Qingyu Wang ◽  
Jon L. Lindsay ◽  
David L. Hofeldt
Keyword(s):  
Boundary Layer ◽  
Temperature Profile ◽  
Population Distribution ◽  
Substrate Surface ◽  
Plasma Jet ◽  
Laser Induced Fluorescence ◽  
Diamond Growth ◽  
Oh Radicals ◽  
Measured Temperature ◽  
Gas Temperature

ABSTRACTThe gas temperature of a radio-frequency thermal plasma has been measured by laser-induced fluorescence along the axis of the plasma jet near the substrate surface. The temperature was determined from the rotational population distribution of OH radicals. From the measured temperature profile, the freestream temperature was found to be about 3400 K and the boundary layer thickness was determined to be about 1 mm. A numerical model including carbonhydrogen- argon kinetics was used to predict species concentrations near the surface of the substrate. The results indicate that all CHa radical concentrations increase with freestream temperature for temperatures between 2500-4000 K. Of the C1 radicals, methyl has the highest concentration in this range in our system, which is consistent with other reports that methyl is an important diamond growth species.

Chemical Vapor Deposition of Silicon Films by Pulsed CO2 Laser Irradiaton of Silane

1983 ◽  
Vol 29 ◽  
Author(s):  
Y. Pauleau ◽  
R. Stawski ◽  
Ph. Lami ◽  
G. Auvert
Keyword(s):  
Laser Beam ◽  
Laser Fluence ◽  
Vapor Deposition ◽  
Incident Angle ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Crystallographic Structure ◽  
Pulsed Co2 Laser ◽  
Quartz Substrates

ABSTRACTSilane molecules have been irradiated by a pulsed CO2 laser operating at 10.59 μm. The threshold of silicon formation by homogeneous dissociation of silane has been investigated as a function of laser fluence (0.1–3.5 J/cm2) and silane pressure (1–100 Torr). Silicon films have been deposited on quartz substrates using the laser beam either perpendicular or parallel to the substrate surface. The crystallographic structure and deposition rate of these silicon films are found to be dependent on the incident angle of the laser beam, silane pressure, substrate temperature and laser fluence. The growth mechanism of these films is discussed.

Effect of Incubation Time on Deposition Behavior of Ruthenium Films by MOCVD Using (2,4-Dimethylpentadienyl)(Ethylcyclopentadienyl)Ruthenium

2009 ◽  
Vol 421-422 ◽  
pp. 87-90 ◽  
Author(s):  
Masaki Hirano ◽  
Kazuhisa Kawano ◽  
Hiroshi Funakubo
Keyword(s):  
Incubation Time ◽  
Deposition Temperature ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Native Oxide ◽  
Organic Chemical ◽  
Deposition Mechanism ◽  
Deposition Amount ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

The deposition mechanism of metal-Ru films including incubation time was investigated for Ru films prepared by metal organic chemical vapor deposition from (2,4-Dimethylpentadienyl)(ethylcyclopentadienyl)Ruthenium (DER) - O2 system. Substrates with amorphous top-layer having various Hf/Si ratio, SiO2 (native oxide)/(001)Si (SiO2), HfSiON/SiON/(001)Si (HfSiON) and HfO2/SiON/(001)Si (HfO2), were used as substrates. The deposition temperature dependence of the deposition amount at the fixed deposition time ranging from 210 oC to 300 oC revealed that the deposition amount depended on the deposition temperature below 250 oC, while it was almost constant above this temperature. Incubation time depended on the kinds of substrate at 210 oC and the substrate surface was fully covered in a shorter time with smaller deposition amount for the substrates with shorter incubation time. In addition, the film with shorter incubation time had smaller surface roughness.

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