Simultaneous Fabrication of Insulator and Contact Holes by Excimer Laser

1991 ◽  
Vol 236 ◽  
Author(s):  
S. Aomori ◽  
M. Murahara
Keyword(s):  
Laser Beam ◽  
Film Thickness ◽  
Excimer Laser ◽  
Chemical Reaction ◽  
Room Temperature ◽  
Excimer Lasers ◽  
Si Substrate ◽  
Krf Laser ◽  
Arf Laser ◽  
Selective Pattern

AbstractA SiO2 insulator and contact holes were simultaneously fabricated at room temperature by ArF and KrF excimer lasers. In this method, NF3 and O2 gases were employed for the reaction gas. When the ArF laser beam irradiated the NF3 and O2 gases in the presence of Si, SiFn and NO2 were produced by photo-chemical reaction. The SiFn adsorbed on the Si substrate pulled out O atoms from the NO2 to form a SiO2 layer. At the same time, the patterned KrF laser beam projected on the substrate and ablated the part exposed to fabricate contact holes. As the results, the simultaneous fabrication of SiO2 insulator with the 700 Å film thickness and selective pattern with the 10 μm width was demonstrated.

Holographic Pattern Etching of Silicon—Carbide by Excimer Laser

1989 ◽  
Vol 158 ◽  
Author(s):  
M. Murahara ◽  
M. Yonekawa ◽  
K. Shirakawa
Keyword(s):  
Laser Beam ◽  
Present Method ◽  
Etching Rate ◽  
The Other ◽  
Laser Beams ◽  
Excimer Lasers ◽  
Holographic Method ◽  
Etching Depth ◽  
Krf Laser ◽  
193 Nm

ABSTRACTThe diffraction grating on SiC mirror was performed by a laser holographic method. In the present method, KrF laser and CIF3 was used for etchant gas. The ClF3 gas has an absorption band in the range between 200 and 400 nm. Therefore, CIF3 gas is effectively decomposed by the XeF, KrF and ArF excimer lasers' radiation. It is found that absorption of Si—C is about 50% in the range of between200 and 400 nm, and that the bonding energy of Si—C is lower than the photon energy of KrF laser beam. The above results indicate the direct decomposition of Si—Cbond. On the other hand, the threshold fluence energy for etching was 800 mJ/cm2 in 249 nm and in 193 nm as high as 7 J/cm2. In these results, the KrF laser is more effective than ArF laser. Then we applied KrF laser to crystalline SiC in an atmosphere of C1F3 gas. The divided two polarized KrF laser beams were interfered on the substrate. And the beams were used to photodissociated CIF3 gas in the proximity of substrate. Fluence of KrF laser beam was 1 J/cm2. The incidential angle of KrF laser beams was 20º and the grating gaps were 7170 Å, etching depth 1000 Å, and etching rate was 5 Å/pulse.

Growth of Transparent SiO2 Thin Film on Silicon at Room Temperatüre by Using I72nm Xe2* Excimer Lamp

1996 ◽  
Vol 446 ◽  
Author(s):  
T. Suzuki ◽  
M. Murahara
Keyword(s):  
Reaction Time ◽  
Chemical Reaction ◽  
Room Temperature ◽  
Specific Resistance ◽  
Relative Dielectric Constant ◽  
Si Substrate ◽  
Chain Reaction ◽  
Experimental Conditions ◽  
Excimer Lamp ◽  
Sio2 Thin Film

AbstractSiO2 insulator was fabricated by using Xe2* excimer lamp at room temperature. In this method, a mixrine of NF3 and O2 gases was employed as a reaction gas. When the NF3 and O2 gases were exposed to the Xe2* excimer lamp light NF3 and O2 gases inside the chamber where Si substrate was placed, SiFn and NO2 were produced by photo‐chemical reaction. The SiFn accumulates on the Si substrate, and SiO2 is formed by oxidation reaction between SiFn and NO2. Subsequently SiFn adheres onto the formed SiO2 and again oxidizes by NO2. These processes occur spontaneously, and on SiO2 film is grown. Experimental conditions were NF3:O2 = 10:1, the total gas pressure 330 torr, photo‐chemical reaction time 5 minutes, and chain reaction time 5 minutes. The results of the film characterization were a SiO2 film thickness of about 1500Å, a refractive index of 1.38, specific resistance of 1.67*1010 Ω cm and relative dielectric constant of 6.96.

Excimer Laser Induced Etching of Silicon-Carbide

1988 ◽  
Vol 129 ◽  
Author(s):  
M. Murahara ◽  
H. Arai ◽  
T. Matsumura
Keyword(s):  
Absorption Band ◽  
Laser Beam ◽  
Excimer Laser ◽  
Etching Rate ◽  
Laser Beams ◽  
Absorption Factor ◽  
Total Flow ◽  
Krf Laser ◽  
Krf Excimer Laser ◽  
Laser Induced Etching

ABSTRACTResistless photoetching of SiC was performed by using XeF and KrF excimer laser beams. In this method, ClF3 gas was used for etchant. C1F3 gas has a unique absorption band in the range of 300- 430 nm. The strongest absorption band corresponds to the wavelength of the XeF laser (350 nm). So C1F3 gas is decomposed effectively. On the other hand, the absorption factor of SiC is about 30% in the range of 200-400 nm, and the bonding energy of SiC is lower than the photon energy of the KrF laser beam. For these reasons, it is possible to cut the bond of SiC directly. Thus, two laser beams were used. Fluence of the KrF laser beam was 200 mJ/cm2, of the XeF, 50 mJ/cm2. Total flow rates through the cell were 0.05 1/min. We can fabricated the etched feature of reticle pattern by reductive projection. Line and space was 10 μm and etching rate was 50Å/pulse.

Microstructure and Thermo-Mechanical Behavior of NiAl Coatings

2004 ◽  
Vol 842 ◽  
Author(s):  
G. Dehm ◽  
J. Riethmüller ◽  
P. Wellner ◽  
O. Kraft ◽  
H. Clemens ◽  
...  
Keyword(s):  
Solid Solution ◽  
Film Thickness ◽  
Mechanical Behavior ◽  
Room Temperature ◽  
Dispersion Strengthening ◽  
Si Substrate ◽  
Temperature Stresses ◽  
Sputter Deposited ◽  
Base Superalloy

ABSTRACTIn this study the thermo-mechanical behavior of a commercial Pt containing NiAl coating deposited on a Ni-base superalloy is compared with a Ni-rich NiAl coating sputter-deposited on a Si substrate. Both types of coatings possess high tensile room temperature stresses after thermal straining. The Pt-NiAl coating shows negligible plasticity as a result of solid solution and dispersion strengthening. In contrast, for the NiAl coatings on Si noticeable plasticity can be obtained if the film thickness exceeds the sub-micrometer range.

Resistless Etching of SiO2 by Two Color Excimer Lasers

1991 ◽  
Vol 236 ◽  
Author(s):  
T. Obara ◽  
M. Murahara
Keyword(s):  
Absorption Band ◽  
Excimer Laser ◽  
Laser Light ◽  
Excimer Lasers ◽  
Etching Pattern ◽  
Thermal Oxide ◽  
Krf Laser ◽  
Arf Excimer Laser

AbstractResistless etching of thermal oxide silicon filmes were demonstrated by ArF & KrF excimer lasers, and CC12F2 gases. CC12F2 was decomposed by ArF excimer laser light, and CF2 radicals were produced. These radicals, which have absorption band nearby 250nm, were vary stable. Then the circuit pattarned KrF laser light was irradiated on the SiO2 in an atomsphere of CF2 radicals. As thse result, the etching pattern of 2 μ m width was performed.

Inactivation of Bacillus subtilis Spores on Aluminum and Polyethylene Preformed Cartons by UV-Excimer Laser Irradiation

2000 ◽  
Vol 63 (6) ◽  
pp. 753-757 ◽  
Author(s):  
K. WARRINER ◽  
G. RYSSTAD ◽  
A. MURDEN ◽  
P. RUMSBY ◽  
D. THOMAS ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Laser Beam ◽  
Excimer Laser ◽  
Laser Light ◽  
Excimer Lasers ◽  
Uv Laser ◽  
Irradiation Treatment ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser ◽  
Optimized Conditions

The efficacy of UV KrF-excimer laser light (at 248 nm) to inactivate Bacillus subtilis spores loaded onto preformed cartons was found to be dependent on the interior carton coating and scheme by which the irradiation was applied. When the carton was held static during UV laser treatment, the majority of the dose was delivered to the base of the carton and to a lesser extent to the upper part of the pack. In this arrangement no irradiation of the interior sides of the carton was observed. A more even distribution of dose was achieved, however, by moving the carton within the laser beam during irradiation treatment. The distribution of UV was also found to be dependent on the type of carton interior coating. With aluminum cartons the dose measured was found to be significantly greater (P < 0.01) and more evenly distributed across the interior compared to when polyethylene packs were tested. Under optimized conditions no spore survivors were detected on aluminum cartons preloaded with 9.5 × 105 B. subtilis spores by applying a UV laser output dose of 160 J. In comparison, the same conditions only achieved a significantly lower (P < 0.01) reduction in spore numbers (log count reduction 4.2) when polyethylene cartons were used. This difference in lethality and UV distribution of laser light was associated with the higher internal reflection of photons with aluminum cartons. The suitability of UV-excimer lasers for sterilizing preformed cartons over traditional germicidal lamp-based methods is discussed.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

A crystallographic analysis of the CoSi/Si(111) interface using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 574-575
Author(s):  
A.C. Daykin ◽  
C.J. Kiely ◽  
R.C. Pond ◽  
J.L. Batstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Theoretical Method ◽  
Crystallographic Analysis ◽  
Si Substrate ◽  
Transmission Electron ◽  
Theoretical Predictions

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

High Resolution Displacement of Functional Groups onto Fluorocarbon Resin Surface by Using ArF Excimer Laser

1996 ◽  
Vol 451 ◽  
Author(s):  
T. Shimizu ◽  
M. Murahara
Keyword(s):  
Contact Angle ◽  
High Resolution ◽  
Laser Beam ◽  
Thin Layer ◽  
Functional Groups ◽  
Excimer Laser ◽  
Laser Fluence ◽  
Large Area ◽  
Three Solutions ◽  
Arf Excimer Laser

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.

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