Abstract: A process for forming a protective polyimide layer over a semiconductor substrate includes the steps of curing a deposited polyamic acid layer at a temperature which is sufficient to reduce the etch rate of the acid layer when subsequently exposed to a developer. After formation of a photoresist masking layer over the polyamic acid, the substrate is exposed to a developer to define a plurality of bonding pad openings therein. The developer permeates into the acid layer to form a salt in the regions beneath the openings. Subsequent hardbaking imidizes the polyamic acid, but not the salt regions. Removing the photoresist layer also develops the polyimide which removes the salt regions to expose the underlying bonding pads.
June 5, 1992
Date of Patent:
September 7, 1993
Maxine Fassberg, Melton C. Bost, Krishnamurthy Murali, Peter K. Charvat, Lynn A. Price, Robert C. Lindstedt
Abstract: Disclosed is a process for forming a pattern of metallization on a processed semiconductor substrate, under high temperature conditions, employing a polyimide precursor material as a lift-off layer. Advantageously, the material is photosensitive, and, after exposure and development, the portions of the layer remaining on the substrate can be completely and readily removed with conventional solvents.
October 6, 1989
Date of Patent:
April 9, 1991
International Business Machines Corporation
Abstract: A method for planarizing surfaces in multi-layered semiconductor structures using elevated features in the form of semiconductor materials, such as for forming heterojunctions, or interconnection metal. A process of forming the features includes leaving residual photoresist on the features. After feature formation and definition of transistor or other structure locations, dielectric material is deposited across the structure. Remaining photoresist is subsequently removed along with dielectric deposited thereon leaving dielectric between the features. A layer of polyimide is spun on the structure and into depressions between the dielectric and features. Typically material deposition, etching, dielectric backfilling and spin-coating steps are repeated until a predetermined number of contact or conductivity regions or interconnection metal layers are formed in the desired multi-layered structure.
Abstract: A thin film bilayer composite source comprises a deposited impurity source layer, e.g. Si or Sb, heavily doped with a diffusion enabling agent, e.g. As, and capped with a passivating layer, e.g. Si.sub.3 N.sub.4, SiO.sub.2, AlN or SiO.sub.x N.sub.y. In a preferred embodiment, a thin film bilayer composite source comprises a Si layer on the surface of said structure vapor deposited at a temperature in excess of 500.degree. C. in the presence of a source of As to hevily dope the layer in the range of 5%-20% atomic weight and a thin cap layer of Si.sub.3 N.sub.4 deposited on the Si layer at a temperature in excess of 500.degree. C. having a thickness only sufficient to prevent the outdiffusion of Ga and As, which thickness may be about 400 .ANG.-700 .ANG.. An important aspect of the employment of this bilayer composite source as a diffusion source for III-V structures is that the composite source is initially deposited at high temperatures, above 500.degree.0 C., i.e.
Abstract: A method of manufacturing a "two-level" solid-state image pickup device wherein a portion of a first metallic electrode electrically connected to a signal storage region is made to project to the highest position above a substrate on which it is formed. A coating of an organic insulating film is then applied to produce a flat surface. The entire surface of the organic film is then etched to expose the projections of the first metallic electrode. A second metallic electrode constituting a pixel electrode is connected to the first electrode at the exposed portion thereof.
Abstract: The disclosure relates to a semiconductor substrate having an active area for formation of an IMPATT device which is formed as a plurality of separated fingers having a common n+ region to spread the area over which the IMPATT is disposed and which provides such additional area for dissipation of heat through the substrate.
Abstract: The disclosure relates to a monolithic circuit and method of making same which includes the use of two substrates of different semiconductor materials or two substrates of the same semiconductor material wherein the processing steps required for certain parts of the circuit are incompatible with the processing steps required for other parts of the circuit.