Showing papers on "Fabrication published in 1981"

A new bird's-beak free field isolation technology for VLSI devices

Abstract: A new field isolation technology ide-- al for VLSI devices has been developed incorporating a unique two step oxide-burying process. This technology is completely free from bird's beak formation which is particularly important for increasing the packing density. A near-perfect planar surface structure is also obtained. MOS devices fabricated by the new technology showed no thershold voltage increase due to the narrow channel effect for channel widths down to submicron region.

Very-high-speed back-illuminated InGaAs/InP PIN punch-through photodiodes

Abstract: Long-wavelength back-illuminated PIN photodiodes capable of detecting optical signals at multigigabit modulation rates have been fabricated and tested in a stripline circuit. A transit-time-limited response time of about 30 ps has been realised in a 25 μm-diameter diode.

A polyacetylene:aluminum photodiode

Abstract: The fabrication of a 1‐cm2 (CH)x:Al Schottky photodiode with junction internal conversion efficiency of 0.30% and quantum efficiency approaching unity (hn≳2.8 eV) is reported. Device characteristics are presented. The effect of oxygen contamination is also discussed.

Process and structure for minimizing delamination in the fabrication of multi-layer ceramic substrate

Abstract: A process and a solid plane structure for minimizing delamination during sintering in the fabrication of multi-layer ceramic substrates, wherein the solid plane structure is designed to obtain maximum ceramic to ceramic interface contact.

Integrated circuit having a sublayer electrical contact and fabrication thereof

Abstract: An integrated circuit containing a refractory metallic silicide beneath a field isolation region and in electrical contact with electrical conductive regions of active impurity dopants in a semiconductive substrate; and process for the fabrication thereof.

Fabrication Technology of Superconducting Material

Abstract: The development and fabrication of technical superconductors for practical applications is closely connected with the physical properties required for the construction of high field magnets

Plasma pretreatment to improve resist properties by reduction of resist flow during postbake

Abstract: Softening and subsequent flowing of resist during postexposure baking, used to promote resist adhesion, often results in reduced resolution and linewidth control. This is unacceptable for the fabrication of very fine feature VLSI devices since linewidth variations of 0.5–1.5 μm can be observed under certain baking conditions. Treatment of positive and negative resists with a nitrogen plasma prior to postbaking reduces resist flow significantly and enables linewidth integrity to be maintained. Minimal resist erosion occurs upon plasma treatment. In one example a series of 1.4‐μm‐diam windows were exposed and developed in 0.8‐μm‐thick HPR‐204 positive photoresist. Samples treated with a 400 W unshielded nitrogen plasma for 10 min exhibited no change in feature width whereas the untreated control, baked as above, exhibited completely closed windows due to excessive resist flow. A model is proposed to account for the improved flow characteristics.

Epitaxial crystal fabrication of SiC:AlN

Abstract: Crystals of silicon carbide and aluminum nitride, substrates containing same, and the fabrication thereof.

Analysis of planar optical waveguide fabrication by ion exchange in glass

Abstract: Fabrication of planar optical waveguides by silver-ion exchange in glass, and the resulting refractive index profiles related to the fabrication conditions, are investigated. The second-order polynomial profile model proposed by Stewart et al. [3] is confirmed, and the dependence of the model characteristics on fabrication conditions is analyzed. Use of the resulting relationships is demonstrated by the compilation of a design table of expected waveguide mode structures for given fabrication conditions. Methods of exchanged-ion concentration profile determination are reviewed and a simple method based on sample angle lapping is proposed.

An improvement of the interface properties of plasma anodized SiO 2 /Si system for the fabrication of MOSFET's

Abstract: A new annealing process in chlorine ambient produced by passing argon through a CCl 4 container for reducing the interface states of the plasma anodized SiO 2 /Si system was developed. At optimum annealing conditions, the interface state density was reduced to about 10 10 states/eV . cm2. Application of the oxide to the fabrication of MOSFET's shows that the devices obtained have lower threshold voltage and higher mobility than those fabricated with thermal oxidation in dry oxygen.

Ptfe compositions containing anisotropic melt-forming polymers

Abstract: Compositions containing a polymer of PTFE and a polymer capable of exhibiting an anisotropic melt characterized in that the compositions contain between 0.05 and 99.5% of PTFE and 0.5 to 99.95% by weight of the polymer capable of forming an anisotropic melt. The presence of a minor amount of the anisotropic melt-forming polymer, that is, from 0.5 to 50% by weight of the composition enables the processability of PTFE to be improved, even to the extent of providing an injection mouldable PTFE composition. Compositions containing 20 to 50% by weight of PTFE confer benefits on anisotropic melt-forming polymers, such as lubricity and greater versatility in fabrication operations. Concentration of 0.05 to 5.0% by weight of PTFE are particularly suitable for modifying the viscosity characteristics of the low melt viscosity anisotropic melt-forming polymers so that such anisotropic melt polymers are less subject to problems such as flashing and jetting during moulding.

Fabrication procedure using arsenate glasses

Abstract: A fabrication technique is described for making various devices in which a certain type of glass is used as a surface protection layer. The glass layers are formed by particle bombardment (generally sputtering or E-beam) of a glass target. Devices with such surface layers are also described. Such glass layers are highly advantageous as encapsulating layers, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures (i.e., in diffusion doping procedures) without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc., and can be removed by standard etching techniques.

Infrared target design: fabrication considerations.

Abstract: The fabrication issues involved in the design of an infrared target are presented.

Masked and selective thermal oxidation of GaAs‐Ga1−xAlxAs multilayer structures

Abstract: The masked thermal oxidation of GaAs was carried out successfully with stripe Cr‐Au metal film as a mask. The oxidation rate of Ga1−xAlxAs was found to be much smaller than that of GaAs; this fact means that the thermal oxidation process is selective for the GaAs‐Ga1−xAlxAs multilayer structure. By means of this masked and selective thermal oxidation (MSTO) technique, the stripe optical waveguides of GaAs and stripe GaAs‐Ga1−xAlxAs double‐heterostructure (DH) lasers were fabricated. A demonstration of the stripe guide and some performance of stripe DH lasers are presented.

Double flow reheat diaphragm

Abstract: In a double flow section of a steam turbine, the inner web of the diaphragm surrounding the rotor shaft in the region of divergence of the steam flow paths, is fabricated in the form of two cylindrical shells which are held together either in a fixed position or in a relatively fixed position which permits some slight axial motion between the shells. This form of diaphragm eliminates a number of machining and fabrication alignment problems and additionally permits differential axial expansion of the two pieces occurring as a result of internal thermal steam conditions.

Double‐shell inertial confinement fusion target fabrication

Abstract: Double‐shell targets may be required for the next generation of inertial confinement fusion targets since the energy available for driving the implosion is limited with current drivers. The use of double‐shell targets to provide a velocity multiplication driven implosion is an alternative to increased driver energy. First generation hemishells, from which spherical shells are constructed, were fabricated by micromachining coated mandrels and by molding. The remachining of coated mandrels will be described in detail in this article. Techniques were developed for coating the microsized mandrels with polymeric and metallic materials by methods including conformal coating, vapor deposition, plasma polymerization and thermoforming. Micropositioning equipment and bonding techniques have also been developed to assemble the hemishells about a fuel pellet maintaining a spherical concentricity of better than 2 μm and voids in the hemishell bonding line of a few hundred angstroms or less.

Fabrication of polyimide masks for x-ray lithography

Abstract: The dimensional stability of a polyimide membrane is a key to the successful fabrication of x‐ray masks. It depends upon fractionation, purification, and the degradation prevention of polyamic acid. The polyimide membranes thus obtained have a great tensile stress so that the membrane flatness and distortion in a 30×40 mm rectangular window area are less than 1 μm and 0.2 μm, respectively. The advantages of using a polished glass plate as a substrate are good flatness, low cost, ease of fabrication, and also that the masks’ dimensions can be made large enough at will.

Flat sealed type battery and its fabrication

Abstract: PURPOSE:To ease the output of current from a battery and improve its leakproofness by providing a flat part on a negative can having a terminal plate, and sealing it with a gasket coated with a sealing agent and a positive can in such a manner that the flat part is sandwiched therebetween. CONSTITUTION:Positive electrode active material 12 of a substance such as silver oxide and a separator 13 are contained in a positive electrode can 11, and negative electrode active material 14 of zinc gel in a negative electrode can 15. A gasket 16 with an L-shaped cross-section is placed between both cans 11, 15, a sealing agent layer 17 of a substance such as blown asphalt is provided on the surface of the gasket 16 to form a sealed battery. A terminal plate 19 is fixed on the negative can 15, and an insulation layer 20 is provided on the under surface of the plate 19. The flat part 15' on the outer periphery of the negative can 15 with a projection-shaped cross section of a material such as clad steel plate is sealed by pressing and folding the positive can 11 to press the gasket 16.

Fabrication of metallic glass wire or tube by drawing

Abstract: Much interest has been stimulated in metallic glasses since Duwez and co-workers [1, 2] developed splat quenching methods for making an amorphous structure in alloys. In particular, metallic glasses show an excellent high strength (1300 to 3900MPa) and ductility (180 ~ bending without fracture). Hence by using superior mechanical properties, a large number of practical applications have been considered [3]. However, unfortunately, the shape of the metallic glasses product is still limited to ribbon or wire due to the necessity of having high supercooling although modern technology may remove this limitation in the future. It is the purpose of the present work to remove the above limitation by making another shape of metallic glass from the original as-quenched ribbon. We will present the first report of the success in making a round cross-sectional wire from an asquenched metallic glass ribbon with a semi-circular cross-section. The metallic glasses, Fe29Ni49P14B6Si2 (2826B METGLAS| are prepared by a rapid quenching method from the molten alloys. The resultant ribbon filaments, 0.24ram wide and 40/~m thickness, are drawn through diamond dies in several steps (0.152 to 0.076mm in diameter). The continuous profile change of the cross-section in each step and the appearance of deformation bands are observed by optical microscope. The samples before and after being drawn to a final stage were pulled to failure at room temperature with a strain rate of ~ = 4 x 10 -4 sec -I using an Instron tensile machine. The nature of the fracture surfaces was examined by scanning electron microscopy. Focusing on the ductility of metallic glass, an as-quenched Ni-Fe base ribbon sample was drawn through diamond dies in several steps (0.152 to 0.076mm in diameter). Fig. la to d shows the continuous micrographic observations of both cross-sections (left on the photos) and the corresponding side surfaces on the samples (right on the photos) during the drawing process. As expected, but surprisingly, the original semicircular cross-section tends to be bent, continuously changing the shape itself and finally reaches a wholly round cross-sectional wire without a break.