Showing papers on "Isotropic etching published in 1969"

Growth and Characterization of Spinel Single Crystals for Substrate Use in Integrated Electronics

Abstract: An extensive study has been made on the growth and characterization of single‐crystal magnesium aluminate spinel. This material has received attention as a superior substrate for epitaxial silicon‐integrated electronic devices. Large spinel single crystals within the compositional range MgO:Al2O3–MgO:3Al2O3, have been successfully grown by flame fusion using a modern three‐tube post‐mix‐type Verneuil burner. Substrate wafers of (111), (100), and (110) orientations were prepared for silicon epitaxy. Surface preparation of the substrates was studied, including mechanical polishing, hydrogen annealing, and chemical etching. The composition, lattice parameter, crystalline perfection, mechanical hardness, thermal stability, and dielectric properties of the spinel single crystals have been characterized by various techniques in an effort to obtain a basic understanding for substrate use of this material system. Some trends in the dependence of these properties on composition were observed. In particular, the th...

Ion‐bombardment‐enhanced etching of silicon

Abstract: A method is described which permits rapid and precise selective etching of silicon crystal surfaces without protecting any part of the surface during the etch procedure. Prior to the etching process the areas to be etched are subjected to an ion‐bombardment treatment, which increases the etch rate in the bombarded surface layer compared to the etch rate of untreated silicon. Etching characteristics for silicon crystals bombarded with neon and argon are presented and shown to agree with theoretical predictions based on a simple model in which the etching characteristics are related to implantation‐produced cluster damage.

Etching composition indication

Abstract: In the etching through a protective glass coating to expose an underlying metal, overetching is prevented by adding a polyhydric alcohol, for example glycerin, to a glass etchant, which causes a color change on a metal, for example aluminum or molybdenum, indicating that etching through the glass coating has been completed.

Resistant system suitable for controlling etching without the aid of an etchant

Abstract: An etching system having sets of prearranged nozzles for dispensing etchant onto preformed masks in a predetermined pattern to allow an operator to controllably enlarge the apertures in a preformed mask without the aid of an etchant resist.

Methods of etching semiconductor body surfaces

Abstract: A METHOD OF ETCHING DESIRED PORTIONS OF A MONOCRYSTALLINE SILICON BODY IN WHICH AN ANISOTROPIC ETCH CONSISTING OF WATER AND AMINE IS EMPLOYED AND SUFRFACE PORTIONS OF THE SILICON BODY ARE PROTECTED WITH A COATING OF ALUMINUM.

Chemical etching solution for printed wiring boards

Abstract: A CHEMICAL ETCHING SOLUTION PARTICULARLY ADAPTED TO SELECTIVELY DISSOLVE COPPER FROM LAMINATED PRINTED WIRING BOARDS IN THE PRESENCE OF METALS SELECTED FROM THE GROUP CONSISTING OF TIN, LEAD, NICKEL, GOLD AND ALLOYS THEREOF WITHOUT CAUSING ATTACK OF SUCH METALS CONSISTS OF AN AQUEOUS AMMONIACAL SOLUTION OF A NORMALLY ACIDIC OXIDIZER, THE SOLUTION HAVING AN ALKALINE PH UP TO ABOUT 11.

Method of fabricating film resistors

Abstract: A method of fabricating film resistors on a substrate in order to avoid the unsatisfactory result of unwanted chemical etching of the film resistor material. A film of nichrome is sputtered over a substrate. Nitrogen is then sputtered over the layer of nichrome, resulting in a film of nickel nitride over the nitride film forming three layers of film, the first being a nichrome film applied directly to the substrate, the next being a nickel nitride film and finally a nickel film. The nickel film is then selectively etched by a conventional etching process, in order to form ohmic contacts and calibrate the precise resistance desired as a result of the combination of nickel and nichrome. The assembly is heated to the necessary temperature in a prescribed atmosphere to decompose the nickel nitride, leaving only nickel and nichrome on the substrate.

Lead sulfide ion implantation mask

Abstract: A method for masking semiconductor bodies during the ion beam implantation of contaminants into preselected portions of a semiconductor material. The method involves the deposition of a lead sulfide film onto the surface portion of a semiconductor material and the formation of the film into a mask through the use of conventional photoresist and chemical etching techniques. The lead sulfide masked semiconductor body can then be subjected to an ion implantation operation.

High depth-to-width ratio etching process for monocrystalline germanium semiconductor materials

Abstract: A process for etching high depth-to-width ratio grooves in the surface of monocrystalline germanium-comprising semiconductor material by orienting the material so that the surface to be etched is parallel to a (110) plane of the crystal structure; orienting an etching mask on that surface such that the length of the groove to be etched is parallel to a (111) plane of the crystal which is normal to said surface; and subjecting the semiconductor material to a preferential etchant which attacks fastest in a [110] direction of a germanium crystal and slowest in a [111] direction.

Chemical machining process

Abstract: A process for chemically machining metals, particularly steels and steel alloys, to depths greater than 0.010 inches by using a chemical etching solution. The metal is coated with an etch-resist, exposed to an energy source to harden and bond a predetermined area of the resist to the metal and then developed to remove the unhardened and unbonded resist. The metal is then recoated with resist, again exposed to an energy source to harden and bond the second resist layer to the first resist layer at the aforesaid predetermined area and then developed to remove the unhardened and unbonded resist. The metal is then passed through a chemical etching solution to chemically machine those areas of the metal unprotected by the double layer of resist.

Method for detecting exposure of a base material through an overlying coating

Abstract: The method for determining the completeness of etching of an oxide from a silicon semiconductor device discloses that bare silicon surfaces are hydrophobic while clean freshly etched oxide surfaces are hydrophilic. To determine whether the silicon is exposed, and therefore free of any oxide film subsequent to etching, the device is cooled and subjected to a stream of moist gas and observed under a microscope. If the etching process by which small holes are formed is incomplete, oxide will remain in the hole and therefore a film of condensed water will form in the holes indicating incomplete etching. If the etching process has been properly completed in the holes, bare silicon will remain causing the moisture to form in small droplets. The form of the moisture can be observed through the microscope.

Process and system for etching metal films using galvanic action

Abstract: A metal film to be etched into a pattern comprising relatively fine and uniform lines is secured to a fixture. The film is ordinarily deposited on a rigid substrate. A metal frame is disposed about the edge of the film for certain metals to produce galvanic action during the etching process. The galvanic action increases the rate of etching and produces uniform etching from the outside of the film towards the center. After the film is in place, an etchant is sprayed onto the film at a relatively high velocity and constant temperature until the etching process is complete. A light source, placed behind the film, which is opaque, prior to the etching, is used to observe the etching process so that it can be discontinued when the etched pattern is eliminated.

Process for etching a pattern of closely spaced conducting lines in an integrated circuit

Abstract: Very small patterns may be etched in aluminum or other metal surfaces using photoresist to mask areas of the surfaces where etching is not desired by applying a Werner complex of chromium with a carboxylic acid to the metal surface. The process is particularly useful for etching conducting lines in microminiature semiconductor device fabrication because the chromium complex increases the adhesion of the photoresist to the aluminum sufficiently to improve line resolution in subsequent etching, and does not increase bridging between adjacent conducting lines.

A new method of etching diamond

Abstract: A new method of etching diamond is described which produces rapid etching and etch patterns which are decidedly better and more easily interpreted than those produced by the conventional method. It is also shown that the new method produces etch patterns having the same morphology as that of trigons observed on natural (111) faces and quadrons on (100) natural faces of diamond.

Photosensitive products and ensitised plates for use in

Abstract: Photosensitive products consist of a metallic support (I) suitable for chemical etching coated with at least one layer of a photosensitive polycarbonate (II) formed by the interaction of bis-phenols containing at least 5% divanillalcyclopentanone with phosghene, glutaryl chloride or neopentylbischloroformate. (I) is Zn, Cu, Mg, or alloys of these metals. The presensitised plate is exposed to a ultraviolet source, the layers (portions) of unexposed photosensitive polymer removed and the plate is then etched. The plates may be stored for several years. Insensitive to atmospheric conditions. They do not become sticky by the action of temperature or pressure. Very sensitive to uv light.

Method of making germanium semiconductor device

Abstract: A METHOD OF MAKING A GERMANIUM MESA-TYPE SEMICONDUCTOR DEVICE BY MESA-ETCHING EMPLOYING AS AN ETCHING MASK, A FILM OF SIO2 APPLIED ONTO THE SURFACE OF A GERMANIUM SUBSTRATE. THE SIO2 FILM CAN BE FORMED BY THERMAL DECOMPOSITION OF ORGANO-OXY-SILANE SO AS TO HAVE A THICKNESS OF ABOUT 1000 TO ABOUT 7000 A. THE MESA-ETCHING CAN BE MADE EITHER BY ELECTROLYTIC ETCHING OR BY CHEMICAL ETCHING.