New Technique For Fabrication Research Articles

A novel technique for high aspect ratio high resolution patterning of membranes

This article presents a new technique for fabrication of high aspect ratio metal patterns on membranes. Two modifications of x-ray lithographic techniques have been employed: simultaneous exposure of a photoresist coated on both sides of the membrane, and membrane exposure from back side using a negative tone photoresist. Both methods provide self-aligned masks for pattern transfer into multiple metal layers. Those techniques have been used for fabrication of high aspect ratio Fresnel zone plates for hard x-ray microscopy. 0.15 μm design rule Fresnel zone plates, with gold structure of 1.6 μm thickness have been fabricated.

A new technique for fabrication of OEICs-the etched back planar process-and its application to the fabrication of planar embedded InP-InGaAs p-i-n photodiodes

The etched back planar process utilizes a nonselective reactive ion beam etching (RIBE) technique both for semiconductor layers and for photoresist. Application of the technique to the fabrication of a planar InP-InGaAs embedded p-i-n photodiode is discussed. The groove depth on the wafer was reduced from 5.3 mu to 0.6 mu m, and the wafer was nearly planarized. Estimates based on photoluminescence intensity variation and the characteristics of the fabricated p-i-n photodiode indicate that little damage was incurred during the process. These results indicate that fabrication of planar OEICs by means of this process is feasible.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

New technique for fabrication of low voltage Si Zener diodes

A new technique for fabrication of low voltage Si Zener diodes is suggested, which consists of two successive diffusions (first a deep phosphorus diffusion and then a shallow boron diffusion) into an n-type Si epitaxial layer. Also, a new analytical expression for differential resistance of low voltage Si Zener diodes in the breakdown region is derived, which describes remarkably well the experimental results.

Development of Double Shell Target for Laser Fusion

A new technique for fabrication of a double shell target was developed using a removable paraffin mandrel. The outer shell was parylene (160-260μm in diameter, 4-10μm in wall thickness) and the inner shell was a glass microballoon (80-160μm in diameter, 1-4μm in wall thickness). Arbitrary gases can be loaded between the outer and inner shells. Detail technique and problems to be improved are reported.

New technique for electron-tunneling junction fabrication and its application to tantalum and niobium

A new technique for the fabrication of electron-tunneling junctions is presented. Ion etching is used to provide a hole in an insulating layer to define the junction area and to produce a clean surface of the underlying superconductor, as indicated by Auger-electron spectroscopy, prior to the barrier formation and the evaporation of the counterelectrode. Knee structure in the current-voltage characteristics of Ta -- Ta/sub x/O/sub y/ -- Pb and Nb -- Nb/sub x/O/sub y/ -- Pb tunneling junctions above the voltage corresponding to the sum of the energy gaps is shown to be due to a proximity effect between a thin ion-implanted normal layer and the underlying superconductor, and can be explained quantitatively using McMillan's theory of the proximity effect. Lowering the energy of the etching ions is shown to reduce the thickness of this normal layer and the associated proximity-induced structure in the tunneling characteristics, so that good values for ..delta../sub Ta/ and ..delta../sub Nb/ are obtained. It is proposed that the excess current observed below the voltage corresponding to the sum of the energy gaps is due to tunneling through normal regions of Nb or Ta in parallel with tunneling through the superconducting regions.

A new technique for fabrication of Schottky barrier diodes

A new technique for fabrication of Schottky barrier diodes

A New Technique for Fabrication of Ohmic Contacts to GaAs Devices

A simple technique for obtaining reproducible ohmic contacts to n-type GaAS is described. It is shown that a particular alloy of gold-germanium, when evaporated onto the hot substrate under specified conditions, yields ohmic contacts with extremely low series resistance. The contact resistance was then separated from the bulk resistance of the semiconductor. The specific resistance of contacts thus made was about 2.32 × 10-5 ohm-cm2. The experimental observations are shown to be in close agreement with a theoretical model based on quantum mechanical tunneling. Phase diagrams and related metallurgical considerations are also discussed.

New Techniques for Fabrication of Airborne Electronic Equipment

New techniques, materials, and methods for the fabrication of airborne electronic equipment as applied to a particular equipment, which have been developed at the National Bureau of Standards, are described. Emphasis has been placed in attaining reliable equipment performance, and steps taken to achieve reliability are discussed. A miniature radar set has been developed using these new techniques and materials. The equipment is capable of operating in an ambient temperature as low as -65 degrees C., and much higher than +55 degrees C. Internal temperatures are minimized by an internal cooling system which is provided to cool the equipment under the high ambient temperature conditions. The equipment is pressurized, and is not limited by altitude. It consists of a single major unit plus accessories. The weight of the entire system is fifty-five pounds.