摘要:
A trench MOSFET transistor device and a method of making the same. The device comprises: (a) a silicon substrate of first conductivity type; (b) a silicon epitaxial layer of first conductivity type over the substrate, the epitaxial layer having a lower majority carrier concentration than the substrate; (c) a trench extending into the epitaxial layer from an upper surface of the epitaxial layer; (d) an insulating layer lining at least a portion of the trench; (e) a conductive region within the trench adjacent the insulating layer; (f) a body region of second conductivity type provided within an upper portion of the epitaxial layer and adjacent the trench; (g) a source region of first conductivity type provided within an upper portion of the body region and adjacent the trench; (h) an upper region of second conductivity type within an upper portion of the body region and adjacent the source region, the upper region having a higher majority carrier concentration than the body region; and (i) a source contact region disposed on the epitaxial layer upper surface, wherein the source contact region comprises a doped polycrystalline silicon contact region in electrical contact with the source region as well as an adjacent metal contact region in electrical contact with the source region and with the upper region.
摘要:
The present invention is directed to a lead-frame having a stack of semiconductor dies with interposed metalized clip structure. Level projections extend from the clip structure to ensure that the clip structure remains level during fabrication.
摘要:
A closed cell trench power MOSFET has a trench (54) running in first and second perpendicular directions through a body region (48) and extending into an epitaxial region (46). The trenches meet to form intersections (16). A polysilicon layer (58) is deposited in the trench. A photoresist pattern (60) is formed over the intersections to inhibit removal of the conductive material from the trench in and around the intersection areas. The process of inhibiting removal of the conductive material over the intersection areas of the trench prevents formation of a depression in the polysilicon in and around the intersection which would increase resistivity in the gate region. The goal of preventing formation of depressions in the polysilicon can also be achieved by making the polysilicon thicker on the intersections prior to the etching process and by making the trenches narrower in and around the intersections.
摘要:
A high voltage silicon rectifier includes a substrate portion and an epitaxial mesa portion that is a frustrum of a pyramid with a substantially square cross section and side walls that make a forty five degree angle with the substrate portion. The mesa portion includes three germanium doped layers that introduce strain to speed up recombination of charge carriers. The topography of the base region of the rectifier has a high-low junction that includes a central portion that is deeper in the mesa than the germanium-doped layers and an edge portion that is shallower in the mesa than the germanium-doped layers and forms a positive bevel angle with the tapered side walls of the mesa,
摘要:
A continuous molding machine particularly adapted for but not limited, in principle, to the making of waffles includes a lower conveyor carrying a plurality of forms each constituting a first part of a respective two-part split mold, a second conveyor carrying a plurality of forms each constituting the other part of the respective split molds and means for guiding the respective conveyors in respective paths so that the first and second mold parts are carried from spaced apart positions to positions in which the parts meet in registry and each of the molds defined by the parts is thereby closed and then the first and second mold parts are carried away from each other again so that each of the molds is opened. The conveyors carrying the mold parts may be passed through an oven to different extents so that the respective conveyors are heated differently and means are provided for aligning the mating mold parts despite different thermal expansions of the conveyors. Means may be provided for facilitating or positively effecting partial opening of the closed molds to permit the release of gases or vapors contained in the molds. Means may be provided for permitting the closed molds to partially open to release gases or vapors contained therein only upon the reaching of a predetermined minimum gas or vapor pressure in the mold. Means may be provided for swinging the mold parts out of the plane of the conveyor on which they are carried in order to facilitate such operations as cleaning of the mold parts.
摘要:
The present invention is directed to a lead-frame having a stack of semiconductor dies with interposed metalized clip structure. Level projections extend from the clip structure to ensure that the clip structure remains level during fabrication.
摘要:
Significant reduction in the cost of fabrication of shallow junction, Schottky or similar semiconductor devices without sacrifice of functional characteristics, while at the same time achieving the advantages is achieved, after the non-polishing cleaning step is essentially performed, by subjecting the substrate to conditions which move disadvantageous factors within said substrate into a space substantially at said surface, followed by substantially removing said factor-containing space from said substrate chemical removal step, followed etching and vapor deposition steps. Although these new steps add time, and therefore cost, to the overall process, the devices under discussion when produced by known industry processes require yet more time, and involve yet more expense, so that the total process represents a substantial reduction in the cost of their manufacture while producing devices which are the equivalent or superior in electrical performance to such devices which are made by known industry processes.
摘要:
Transient voltage suppressor semiconductor devices and other semiconductor devices having rigorous requirements for the diffusion and depth of impurities to produce P-N junctions can be fabricated at surprisingly low costs without sacrifice of functional characteristics by subjecting the substrate to a grinding process resulting in a surface short of polishing perfection, thereby to eliminate the time-consuming and hence costly conventional polishing operation, and then diffusing the desired impurity into the substrate from a solid impurity source.