General Semiconductor, Inc.

Other

Alpha Omega Semiconductor Inc.

General Instrument Corporation of Delaware

John Amato

Fwu-Iuan Hshieh

Koon Chong So

Yan Man Tsui

Dennis Garbis

Joseph Y Chan

Gregory Zakaluk

Jack Eng

Anup Bhalla

Hamza Yilmaz

Jun Lu

Yueh-Se Ho

Yan Xun Xue

Kai Chieh Liu

Xiaotian Zhang

Willem G Einthoven

Brian D Pratt

William John Nelson

Jun Wu

Lawrence LaTerza

Louis Siegel

Charles A Hirsch

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.

Stacked dual chip package having leveling projections

Stacked dual chip package and method of fabrication

A method of forming a trench MOSFET device includes depositing an epitaxial layer over a substrate, both having the first conductivity type, the epitaxial layer having a lower majority carrier concentration than the substrate, forming a body region of a second conductivity type within an upper portion of the epitaxial layer, etching a trench extending into the epitaxial layer from an upper surface of the epitaxial layer, the trench extending to a greater depth from the upper surface of the epitaxial layer than the body region, forming a doped region of the first conductivity type between a bottom portion of the trench and substrate, the doped region having a majority carrier concentration that is lower than that of the substrate and higher than that of the epitaxial layer, wherein the doped region is diffused and spans 100% of the distance from the trench bottom portion to the substrate, forming an insulating layer lining at least a portion of the trench, forming a conductive region within the trench adjacent the insulating layer and forming a source region of said first conductivity type within an upper portion of the body region and adjacent the trench.

Method of making a trench MOSFET device with improved on-resistance

A trench DMOS transistor device that comprises: (a) a substrate of a first conductivity type; (b) an epitaxial layer of first conductivity type over the substrate, wherein the epitaxial layer has 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 a second conductivity type provided within an upper portion of the epitaxial layer and adjacent the trench; (g) a source region of first conductivity type within an upper portion of the body region and adjacent the trench; and (h) one or more low resistivity deep regions extending into the device from an upper surface of the epitaxial layer. The low resistivity deep region acts to provide electrical contact with the substrate, which is a common drain region for the device. By constructing a trench DMOS transistor device in this fashion, source, drain and gate contacts can all be provided on a single surface of the device.

Trench DMOS device with improved drain contact

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.

Trench MOSFET device with polycrystalline silicon source contact structure

A method of forming a trench within a semiconductor substrate. The method comprises, for example, the following: (a) providing a semiconductor substrate; (b) providing a patterned first CVD-deposited masking material layer having a first aperture over the semiconductor substrate; (c) depositing a second CVD-deposited masking material layer over the first masking material layer; (d) etching the second masking material layer until a second aperture that is narrower than the first aperture is created in the second masking material within the first aperture; and (e) etching the semiconductor substrate through the second aperture such that a trench is formed in the semiconductor substrate. In preferred embodiments, the method of the present invention is used in the formation of trench MOSFET devices.

Method of forming narrow trenches in semiconductor substrates

A trench MOSFET device and method of making the same. The trench MOSFET device comprises: (a) a substrate of a first conductivity type; (b) an epitaxial layer of the first conductivity type over the substrate, wherein the epitaxial layer has a lower majority carrier concentration than the substrate; (c) a trench extending into the epitaxial region 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 doped region of the first conductivity type formed within the epitaxial layer between a bottom portion of the trench and the substrate, wherein the doped region has a majority carrier concentration that is lower than that of the substrate and higher than that of the epitaxial layer; (g) a body region of a second conductivity type formed within an upper portion of the epitaxial layer and adjacent the trench, wherein the body region extends to a lesser depth from the upper surface of the epitaxial layer than does the trench; and (h) a source region of the first conductivity type formed within an upper portion of the body region and adjacent the trench. The presence of the doped region lying between the bottom portion of the trench and the substrate (also referred to herein as a &ldquo;trench bottom implant&rdquo;) serves to reduce the on-resistance of the device.

Trench MOSFET device with improved on-resistance

A method is provided for forming shallow and deep dopant implants adjacent source regions of a first conductivity type within an upper portion of an epitaxial layer in a trench MOSFET device. The method comprises: (a) forming a patterned implantation mask over the epitaxial layer, wherein the patterned implantation mask comprises a patterned insulating region and covers at least a portion of the source regions, and wherein the patterned implantation mask has apertures over at least portions of the epitaxial layer adjacent the source regions; (b) forming shallow dopant regions by a process comprising: (1) implanting a first dopant of a second conductivity type at a first energy level within an upper portion of the epitaxial layer through the apertures and (2) diffusing the first dopant at elevated temperatures to a first depth from an upper surface of the epitaxial layer; (c) forming deep dopant regions by a process comprising: (1) implanting a second dopant of the second conductivity type at a second energy level within an upper portion of the epitaxial layer through the apertures and (2) diffusing the second dopant at elevated temperatures to a second depth from the upper surface of the epitaxial layer; and (d) enlarging apertures in the patterned insulating region. In this method, the second energy level is greater than the first energy level, the second depth is greater than the first depth, and the first and second dopants can be the same or different. The method of the present invention can be used, for example, to form a device that comprises a plurality of trench MOSFET cells.

Method for forming trench MOSFET device with low parasitic resistance

In integrated circuits produced by etching and damascene techniques, it is common for cracking to occur in dielectric material surrounding an interconnect metal layer integrated into the device, presumably as a result of the transfer of stresses from the interconnect metal layer to the surrounding dielectric material. The present invention addresses this problem by providing an interconnect metal layer that comprises rounded comers which are believed to reduce the stresses transferred to a surrounding dielectric layer.

Integrated circuit resistant to the formation of cracks in a passivation layer

A trench Schottky barrier and a method of making the same in which the rectifier has a semiconductor region having first and second opposing faces; the semiconductor region having a drift region of a first conductivity type adjacent the first face and a cathode region of the first conductivity type adjacent the second face; the drift region having a lower net doping concentration than that of the cathode region. The rectifier also has a plurality of trenches extending into the semiconductor region from the first face; the trenches defining a plurality of mesas within the semiconductor region, and the trenches forming a plurality of trench intersections. The rectifier further includes an oxide layer covering the semiconductor region on the bottoms of the trenches and on lower portions of sidewalls of the trenches, a polysilicon region disposed over the oxide layer within the trenches, and insulating regions at the trench intersections that cover a portion of the polysilicon region and a portion of the oxide layer.

Trench schottky barrier rectifier and method of making the same

A trench Schottky barrier rectifier and a method of making the same in which the rectifier has a semiconductor region having first and second opposing faces; the semiconductor region having a drift region of first conductivity type adjacent the first face and a cathode region of the first conductivity type adjacent the second face; the drift region having a lower net doping concentration than that of the cathode region. The rectifier also has a plurality of trenches extending into the semiconductor region from the first face; the trenches defining a plurality of mesas within the semiconductor region, and the trenches forming a plurality of trench intersections. The rectifier further includes an oxide layer covering the semiconductor region on bottoms of the trenches and on lower portions of sidewalls of the trenches, a polysilicon region disposed over the oxide layer within the trenches, and insulating regions at the trench intersections that cover a portion of the polysilicon region and a portion of the oxide layer.

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.

Low cost method of fabricating transient voltage suppressor semiconductor devices or the like

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,

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Tracy, CA, United States of America

John Amato