Abstract: A palladium electroplating procedure is disclosed which permits rapid and efficient plating and yields ductile, adherent palladium films. The electroplating bath comprises a unique palladium complex. The procedure is also useful for electroplating a variety of palladium alloys. In addition, the bath is highly stable and does not adversely affect the base material being plated.

Abstract: A process is described for photoelectrochemically etching n-type gallium arsenide and closely related compound semiconductors such as gallium aluminum arsenide and gallium arsenide phosphide. Such a process is advantageous because the etching is confined to where light is incident to the surface of the semiconductor. In addition, the shape of the configuration etched out of the semiconductor can be controlled by the light incident on the surface of the semiconductor. For example, undercutting can be minimized by use of parallel rays incident on the surface of the semiconductor to be etched.

Abstract: Photoelectrochemical processing of semiconductors is highly desirable because of its versatility and simplicity. The invention is a photoelectrochemical etching procedure for n-type silicon in which an alcohol based solution of hydrofluoric acid is used as the electrolyte. This procedure is useful for the fabrication of a variety of silicon devices.

Abstract: A silver electroplating procedure is disclosed which permits rapid and efficient plating and yields ductile, adherent silver films. The electroplating bath comprises silver complexed with an aliphatic polyamine compound with 3 to 20 carbon atoms. Particularly useful are such polyamines as diaminopropane (particularly 1,3-diaminopropane), diethylenetriamine, 1,4-diaminobutane, 1,6-diaminohexane, etc. The procedure is also useful for electroplating a variety of silver alloys. In addition, the bath is highly stable, does not adversely affect the base material being plated and does not contain hazardous materials which require special disposal procedures.

Abstract: Disclosed is a water electrolysis process for producing hydrogen in which a nickel anode is prepared by an electrolytic corrosion procedure. This procedure reduces the anode overpotential by about 0.2 volts at commercially used current densities which leads to greater process efficiency and significant reduction in electrical energy consumption.

Abstract: The addition of certain polymer compounds such as polybenzimidazole increases the capacity and cycle life of cadmium electrodes in nickel-cadmium batteries.

Abstract: A copper electroplating process is described in which the anode is surrounded by a cation-permeable membrane so as to prevent decomposition of additives in the electrochemical bath. Such a feature adds to bath lifetime and permits better control of bath chemistry and plating quality during the electroplating process. The feature is especially advantageous for copper electroplating processes using nonconsumable electrodes because of the high consumption of additives and that the copper can be added to the cathode side of the membrane so that acid copper ions need not pass through the membrane.

Abstract: A process is described for etching a tapered point on a cylindrically symmetric body using an inert liquid layer on top of the etching solution. The process is extremely useful for etching tapered points on optical fibers prior to melt-back to form a small lens to couple light from laser to optical fiber. The process produces excellent tapered points rapidly and reproducibly with a minimum of operator attention and without etch marks above the taper.

Abstract: A process is described for fabricating various optical devices including photodiodes in which a protective dielectric layer is put down on the surface of the device prior to heating to temperatures over about 250-300 degrees C. Such devices have excellent performance characteristics including low dark current and low noise figures.

Abstract: A palladium electroplating process is described in which a unique compound is used to supply palladium to the electroplating bath. The procedure is particularly useful where a polyamine such as 1,3-diaminopropane is used as the complexing agent for palladium in a palladium electroplating bath. The unique compound is palladium-1,3-diaminopropanedichloride which is highly stable, can be made in pure form, and is readily soluble in water, aqueous solutions, and typical palladium baths.

Abstract: Efficient transmission of light through a matrix isolation thin film is obtained despite the fact that the index configuration of the thin film is not appropriate for classical waveguides. The light is transmitted through the film approximately parallel to the substrate, thereby permitting analysis of the thin film, stimulation of reaction within the thin film, or use of the thin film as an optical memory.

Abstract: In traditional copper electroplating processes, soluble copper anodes are used as the source of copper. There are certain potential advantages to using nonconsumable anodes and adding a source of copper such as copper oxide to replenish the electroplating bath. Periodic reverse current plating is used by some manufacturers to obtain smoother deposits without the use of additives. This periodic reversal of current drastically reduces the service life of the nonconsumable anodes because of dissolution of the metal oxide on the insoluble anode. The invention is a copper electroplating process with a dual-element anode assembly. This assembly consists of electrically isolated copper and metal-oxide electrodes. The metal-oxide electrode is active only during the anodic part of the cycle while the copper electrode is active only during the cathodic part of the cycle. Electrical isolation is achieved by the use of diodes or relays.

Abstract: A process is described for the electrodepositon of copper on various surfaces. The process involves use of a nonconsumable counterelectrode. Of particular significance is the composition of the surface of the counterelectrode. The surface of the counterelectrode comprises iridium oxide and tantalum oxide. Such processes can be carried out at high speeds, with smaller and more efficient equipment and can use various copper compounds as a source of copper.

Abstract: A procedure is described for electroplating platinum and platinum alloys. This procedure permits rapid electroplating of platinum and yields platinum films with excellent properties. The electroplating bath comprises a unique platinum complexing agent, namely an organic polyamine compound. The procedure is also useful for electroplating a variety of platinum alloys. In addition, the bath is highly stable and does not adversely affect the base material being plated.

Abstract: A process is described for plating silver on metallic surfaces electrically attached to a compound semiconductor. This process involves a photoelectrochemically induced oxidation reaction in which the compound semiconductor is oxidized and reduction to metallic silver takes place on the metallic surface electrically connected to the semiconductor. This procedure is particularly valuable where silver is to be plated in small holes or crevices in the semiconductor structure. It is particularly valuable because plating is specific to the metallic surface and does not occur on the semiconductor surface. It is useful in providing low inductance electrical connections to various parts of semiconductor devices such as in the source for gallium arsenide field effect transistors. Silver is particularly valuable in such applications because of its chemical inertness, high electrical conductivity and exceptionally high thermal conductivity which permits high transistor power handling capabilities.

Abstract: A process is described for electrolessly plating palladium metal on a variety of surfaces including palladium surfaces. The process involves use of a special electroless plating bath which is sufficiently stable for practical commercial use and yields excellent plating results. The plating bath contains a palladium salt and organic ligand. A narrow class of reducing agents is used including formaldehyde. The bath is made acid generally by the addition of nitric acid or hydrochloric acid. The process yields plating rates of about 6 microinches per minute and plating thicknesses in excess of 1 micrometer.

Abstract: An etching process is described which can etch geometrical shapes on the surface of an n-type or intrinsic compound semiconductor and yield surfaces of optical quality without further processing. The etching process is an electrochemical process where etching is proportional to light intensity. The process involves applying a potential to the compound semiconductor while immersed in an electrolytic solution and irradiating the surface to be etched with light in a certain energy range. The electrolytic solution contains hydrofluoric acid. The distribution of light intensity and ray direction is selected to produce the desired geometrical shape. Particularly advantageous is that the surfaces produced are of optical quality. For example, lenses produced by the etching process exhibit surfaces of optical quality. Further, the process can be carried out on all the lenses on a wafer simultaneously without attention to individual devices. This is highly desirable economically.

Abstract: A procedure is described for electrochemically photoetching n-type and intrinsic compound semiconductors. The process involves applying a potential to the compound semiconductor while it is in contact with an electrolytic solution and irradiating the surface to be etched with light in a certain energy range. By suitable adjustment in the potential, electrolytic solution composition and light energy, the etch rate is made proportional to the light intensity. By suitable variation in light intensity and light-ray direction, various geometrical features can be made on the surface of the compound semiconductor. For example, a hole with straight sides can be made in the compound semiconductor by use of a light spot and parallel (collimated) light rays. An advantageous application of this process is the fabrication of a photodiode with a hole in the center for use in bidirectional communication systems and to monitor power output for optical communication sources.

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.

Abstract: A photoelectrochemical process is described for anisotropic etching of intrinsic III-V compound semiconductors. Such a process is highly advantageous because the etching takes place only where light is incident on the surface of the semiconductor. Thus, various patterns can be etched into the semiconductor surface without the use of a mask, undercutting is minimized where masks are used and the shape of the hole etched out of the surface can be controlled.