Abstract: A pressure sensor includes a pressure sensitive element and associated integrated circuitry on a common silicon chip. Fusible links in a conditioning network of the integrated circuit are opened by electrical pulses applied to pinouts that are accessible for probing in a trough in the support housing that is exposed during the testing and adjusting phase, but is sealed off by the cover in the final assembly so that the pinouts are no longer accessible.
Abstract: A double heterojunction lead salt semiconductor diode laser having an optical cavity of PbEuSeTe alloy with a quantum well having reduced Eu concentration disposed to one side of the optical cavity, the optical cavity having a given lattice constant and index of refraction. The optical cavity is sandwiched between two PbEuSeTe alloy confinement layers that are mutually of opposite conductivity type and have substantially the same lattice constant as the optical cavity. A pn junction surface in the optical cavity and preferably on or adjacent the quantum well layer injects charge carriers into the optical cavity. The larger energy band gap between the quantum well layer and its adjacent sandwiching confinement layer strongly confines charge carriers of one type from recombining in the oppositely doped adjacent sandwiching layer. This results in a decreased threshold current (I.sub.th) and a higher maximum operating temperature.
Abstract: A vertical j-MOSFET useful as a power transistor includes a two-dimensional array of square cells in which a small fraction of the cells are replaced by a double-junction sink useful for collecting the minority carriers in the channel regions that normally will accumulate at each interface of the gate electrode and channel region.
Type:
Grant
Filed:
July 27, 1987
Date of Patent:
May 24, 1988
Assignee:
General Motors Corporation
Inventors:
Stephen J. Valeri, Bernard A. MacIver, Kailash C. Jain
Abstract: Rapid thermal annealing, involving rapid heating to a temperature of between 550 degrees C. and 750 degree C. for between 30 and 90 seconds and rapid cooling, is used to dissolve the precipitates of transition metals which tend to occur in a silicon wafer and to keep such metals in solution after cooling. Such annealing can be used in the manufacture of bipolar transistors to limit the emitter-collector shorting caused by metallic precipitates. It is also useful more generally to improve the leakage current of p-n junctions either in diodes or as parts of bipolar or field-effect transistors.
Abstract: A ceramic member with thick film conductors is mounted on a heat sink and a silicon integrated circuit (chip) is placed through a hole in the ceramic member and is soldered by a back surface (the substrate) to the heat sink. A tape automated bonding lead frame is used to provide conductors that are soldered to bonding pads on the ceramic member and are compression bonded to conductive bumps on the chip and to provide other conductors that are soldered to pads on the ceramic member and crossover a front active surface of the chip. These crossover conductors are air isolated from the chip and allow an increase in interconnect density. The attachment of the semiconductor substrate to the heat sink provides good heat dissipation.
Abstract: Rapid response, highly precise determinations of oxygen partial pressures in internal combustion engines operating with lean air/fuel mixtures are accomplished by using a thin film internal reference, solid electrolyte electrochemical type oxygen sensor comprising laterally disposed galvanic sense and pump cells on a single planar substrate, and an internal reference gas chamber provided by a cap. A cerium dioxide, thin film electrode on the galvanic pump cell provides an oxygen reservoir for the internal reference gas chamber.
Abstract: A piezoresistive pressure transducer is formed in a silicon layer which has been grown over a monocrystalline silicon substrate, a central portion of which had been earlier coated with a silicon dioxide layer having a plurality of apertures under each of which had been formed a heavily doped etch resistant region. The silicon layer is grown epitaxially over the apertures to be monocrystalline but grows as polycrystalline material over the silicon dioxide. Then the silicon substrate is etched to remove its central portion under the silicon dioxide and the heavily doped regions, leaving a thick surrounding portion for support. Resistors are formed in the monocrystalline portions of the grown layer overlying the heavily doped regions.
Abstract: A process for forming MOS transistors in which the source and drain regions essentially interface only the channel portion of the silicon substrate to keep parasitic capacitances low. To this end, a monocrystalline silicon substrate has one major planar surface covered with a layer of silicon oxide and a hole formed in the oxide layer of a size suited for the channel of the transistor. Then silicon is epitaxially grown vertically to fill the hole. The grown silicon is then covered. Next, portions of the oxide layer are removed to expose a pair of opposed vertical sidewalls of the vertically grown silicon and silicon is epitaxially grown laterally out of said exposed sidewalls. Such laterally grown regions serve as the source and drain of the transistor and an upper portion of the vertically grown silicon serves as the channel. A gate oxide is grown over a top portion of the vertically grown silicon and a polysilicon gate region is formed over the gate oxide.
Abstract: An MOS transistor having relatively low parasitic capacitances is achieved by forming a dielectrically isolated mesa on a monocrystalline substrate. Such mesa includes a polycrystalline silicon region that serves as a gate region and an oxide layer that serves as a gate oxide. Subsequently, such mesa is made to sit on a platform, arising from the silicon substrate and surrounded by a sea of silicon dioxide originally at the level of the bottom of the mesa. The level of this sea is lowered to expose opposed sides of the platform to which is grown separate regions of lateral epitaxial silicon that serve as the source and drain of the transistor.
Abstract: A spring steel bayonet type retainer for securing encapsulated semiconductor devices to circuit boards either directly or through an intermediate heat dissipator. The retainer comprises a spring steel body bent approximately centrally and at approximately right angles. At least one portion is slotted to define outboard spring fingers and inboard bayonet type arms which extend through aligned holes in the device and the circuit board. The noncoplanar portions provide clamping forces on the main body of the encapsulated semiconductor device and may be provided with laterally outwardly extending ears to fit closely within the confines of a heat dissipator device to prevent relative rotation therebetween.
Abstract: A method and apparatus for printing through holes in ceramic substrates and the like. The substrate is held in position by means of a vacuum applied to an outer peripheral surface portion thereof. The deposited substance is pulled through the holes in the substrate by means of a closely regulated vacuum applied only to an inner surface portion, the inner and outer vacuum areas being separated in a holder device by means of O-rings. A pressure-time profile which appears in a plenum closely adjacent to the inner chamber may be compared to a previously generated pressure-time profile reference and used to accept or reject parts.
Abstract: Solder flux is applied to the face of a printed circuit board (24) or the like by flowing a foam (30) of liquid flux bubbles upwardly through the top of a chimney flue (10) and into contact with the board face which is top passed over the top of the flue. The size of bubbles adjacent the face of the board is controlled by placing a grid screen (26) within and immediately beneath the top of the flue. The openings (26a) in the grid screen allow passage therethrough of smaller bubbles (34) but prevent passage of larger bubbles (32). The force of the board face on the foam urges the larger bubbles downwardly into contact with the grid screen where the grid wires of the screen pierce and thereby break the larger bubbles into smaller bubbles which then rise to the face of the board.
Abstract: A printing screen for screen printing fabrication substances such as solder paste has an aperture formed therein so that the screen may be placed on a substrate surface with a pre-mounted device extending through the aperture. A metal cap is bonded to the screen over the pre-mounted device to protect the device against damage during a subsequent screen printing operation. Different elements may, therefore, be bonded to a substrate in completely independent steps without the need for fluxing operations in later bonding operations.
Type:
Grant
Filed:
March 24, 1986
Date of Patent:
July 7, 1987
Assignee:
General Motors Corporation
Inventors:
David B. Metzger, Glenn S. Johnson, Michael D. Bramel
Abstract: An integrated circuit is made that includes an insulated gate transistor and a buried contact. The buried contact is used to divide an active device area in two discrete parts, that are doped during source-drain doping in other active device mesas of the integrated circuit. Discrete contacts to these regions, along with the buried contact, provide an additional type of electrical component in the integrated circuit, such as a bipolar lateral transistor.
Abstract: A rapid-response gas sensor for measuring the relative presence of a gas in a mixture of gases and its method of manufacture. The sensor is fabricated using microelectronics technology to form multiple thin-film solid-electrolyte pump and sense cells within a hermetically sealed sensor cavity.
Abstract: A method of making an optically coupled semiconductor laser having cleaved facing end walls and precise alignment and spacing. An indium coated face of a semiconductor laser diode bar is placed on an indium coated support. A knife edge cleaves the bar into two closely spaced and aligned semiconductor diode laser bodies and concurrently cold bonds them to the support. The knife edge is used without deleteriously affecting their bonding to the support.
Abstract: A method is provided for selectively etching ion-implanted silicon dioxide. A masked silicon dioxide layer is exposed to an ion beam of controlled dose and energy. The mask is removed and the silicon dioxide layer is brought in contact with an aqueous ammoniacal hydrogen peroxide solution which preferentially removes the ion-bombarded region with minimal etching of the unimplanted silicon dioxide.
Abstract: A new semiconductor power device, suitable for electrical switching in automotive applications, is proposed. This device combines the low specific on-resistance achievable with bipolar regenerative switching devices with the convenience of insulated gate control of not only turn-on but also turn-off. A device structure is presented that also includes a pinch resistance effect to more rapidly produce turn-off. The anode region of the device is electrically shorted to its contiguous N-type region.
Abstract: An enhancement implant used in late programming of a ROM in an integrated circuit is combined with a depletion implant used much earlier in the fabrication process to also permit late programming of power paths in the integrated circuit. The implants must be matched and the IC heated after the enhancement implant.
Type:
Grant
Filed:
October 23, 1985
Date of Patent:
January 6, 1987
Assignee:
General Motors Corporation
Inventors:
Randy A. Rusch, Douglas A. Kittle, Bernhard G. Ulfers, Stephen L. Inman
Abstract: A new semiconductor power device, suitable for electrical switching in automotive applications, is proposed. This device combines the low specific on-resistance achievable with bipolar regenerative switching devices with the convenience of insulated gate control of not only turn-on but also turn-off. A device structure is presented that also includes a pinch resistance effect to more rapidly produce turn-off.