Using Structure Alterable To Conductive State (i.e., Antifuse) Patents (Class 438/131)
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Patent number: 6146925Abstract: A method of jointly forming stacked capacitors and antifuses includes, a) providing a common layer of electrically conductive material to form both a capacitor storage node and an inner antifuse plate; b) providing a common layer of dielectric material over the capacitor storage node and the inner antifuse plate, the common layer of dielectric material comprising both an intervening capacitor dielectric element and an intervening antifuse dielectric element, the common layer of dielectric material having a first breakdown voltage per unit length value for a given current per unit area; c) providing a common layer of electrically conductive material over the common layer of dielectric material to form both a capacitor cell layer and an outer antifuse plate; d) providing a lateral edge of the outer antifuse plate and a lateral edge of the intervening antifuse dielectric element; and e) depositing an antifuse breakdown layer of dielectric material over the lateral edges of the outer antifuse plate and the intervType: GrantFiled: January 28, 1998Date of Patent: November 14, 2000Assignee: Micron Technology, Inc.Inventor: Charles H. Dennison
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Patent number: 6146999Abstract: A method for forming a metal line of a semiconductor device is suitable for forming a conductive material with strong connection force, by irradiating the region between metals to be connected with each other, with laser beams. It comprises the steps of: forming a plurality of metal lines on a substrate; depositing a first conductive material over the substrate including the metal lines; irradiating the first conductive material between the metal lines to be connected, with laser beams, before forming a second conductive material; and removing the first conductive material excluding the second conductive material.Type: GrantFiled: October 23, 1997Date of Patent: November 14, 2000Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Dong Man Kang, Jung Ho Kang
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Patent number: 6143586Abstract: An electrostatic protected integrated circuit (IC) substrate and a method of making an integrated circuit package with the electrostatic protected IC substrate includes an IC substrate, having a plurality of electrical traces formed on the top of the IC substrate with the electrical traces extending from an IC chip mounting area near the center to the periphery of the IC substrate. Electrically shorting the electrical traces together with a conductive material such as conductive tape or epoxy, thereby, protecting the IC substrate against the accumulation of static charges during the assembly of the IC chip on the IC substrate. The IC chip is mounted in the mounting area on the IC substrate and the conductive material is removed before final testing.Type: GrantFiled: June 15, 1998Date of Patent: November 7, 2000Assignee: LSI Logic CorporationInventors: Chok J. Chia, Patrick Variot, Qwai H. Low
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Patent number: 6124193Abstract: An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.Type: GrantFiled: April 17, 1998Date of Patent: September 26, 2000Assignee: Actel CorporationInventors: Frank W. Hawley, John L. McCollum, Ying Go, Abdelshafy Eltoukhy
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Patent number: 6117694Abstract: A microelectronic component, such as a connector or a packaged semiconductor device is made by connecting multiple leads between a pair of elements and moving the elements away from one another so as to bend the leads toward a vertically extensive disposition. One of the elements includes a temporary support which is removed after the bending operation and after injecting and curing a dielectric material to form a dielectric layer surrounding and supporting the leads.Type: GrantFiled: March 12, 1999Date of Patent: September 12, 2000Assignee: Tessera, Inc.Inventors: John W. Smith, Belgacem Haba
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Patent number: 6103555Abstract: The reliability of an antifuse can be increased and/or the thickness of the antifuse dielectric can be decreased by the use of a rapid thermal nitridation nitride layer as part of the antifuse dielectric. The RTN nitride layer is denser and has fewer pinholes than nitride layers formed by chemical vapor deposition. The rapid thermal nitridation also produces a good contact with a bottom electrode containing silicon as well as providing a nucleation layer for any additional nitride layer formed by chemical vapor deposition. Increasing the reliability of the antifuse dielectric allows it to be thinner, and thus allows for the programming of the dielectric layer at lower programming voltages.Type: GrantFiled: June 10, 1996Date of Patent: August 15, 2000Assignee: Integrated Device Technology, Inc.Inventor: Jeong Yeol Choi
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Patent number: 6096580Abstract: A low programming voltage anti-fuse formed by a MOSFET (or MOS) or by a deep trench (DT) capacitor structure is described. Lowering the programming voltage is achieved by implanting a dose of heavy ions, such as indium, into the dielectric directly on the substrate or indirectly through a layer of polysilicon. The programming voltage can also be lowered on the MOSFET/MOS capacitor anti-fuse by accentuating the corners of active areas and gate areas of the device with suitable layout masks during processing. Silicon active area corner rounding steps should also be avoided in the fabrication of the anti-fuse to reduce the programming voltage. In the DT capacitor, lowering the programming voltage may be achieved by implanting the node dielectric of the DT anti-fuse with heavy ions either directly or through a conformal layer of polysilicon deposited on it or after the first amorphous silicon recess step during the fabrication of the DT capacitor.Type: GrantFiled: September 24, 1999Date of Patent: August 1, 2000Assignee: International Business Machines CorporationInventors: S. Sundar Kumar Iyer, Liang-Kai Han, Robert Hannon, Subramanian S. Iyer, Mukesh V. Khare
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Patent number: 6096579Abstract: A method for controlling the thickness of a passivation layer underlying with a fuse on a semiconductor device is disclosed herein. The anti-reflective coating on a metal layer is buried in the passivation layer, and the fuse is in a semiconductor device. The method includes the following steps. First, use a first etchant and Ar to etch the passivation layer till the anti-reflective coating is exposed, the first thickness of the passivation layer above the anti-reflective coating is smaller than the second thickness of the passivation layer above the fuse. Then, utilize a second etchant to etch the anti-reflective coating till the metal layer is exposed. The second etchant has a selectivity ratio from the anti-reflective coating to the passivation layer being at least 10. The second etchant mentioned above includes BCl.sub.3, Cl.sub.2, O.sub.2, and Ar.Type: GrantFiled: March 25, 1999Date of Patent: August 1, 2000Assignee: Vanguard International Semiconductor CorporationInventors: Wen-Shiang Liao, Wan-Yih Lien
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Patent number: 6069064Abstract: A method and apparatus for forming a junctionless antifuse semiconductor structure comprises forming an antifuse in non-active areas of a semiconductor wafer. In one embodiment, the antifuse is formed over a polysilicon layer, which is coupled to a field oxide layer. In a further embodiment, the polysilicon layer comprises a bottom conductor layer in the antifuse. In another embodiment, a refractory metal silicide layer is formed between the polysilicon layer and the antifuse. In yet a further embodiment, the refractory metal silicide layer comprises the bottom conductor layer in the antifuse.Type: GrantFiled: August 26, 1996Date of Patent: May 30, 2000Assignee: Micron Technology, Inc.Inventors: Douglas J. Cutter, Fan Ho, Kurt D. Beigel
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Patent number: 6057589Abstract: An over-etched (OE) antifuse includes a lower electrode, an antifuse layer contacting the lower electrode by an over-etched via, and a second conductive layer formed on the antifuse layer. This over-etched via forms a trench in the lower electrode, wherein in one embodiment the depth of the trench approximates the thickness of the antifuse layer. The trench narrows the programming voltage distribution of the antifuses on the device, irrespective of topology. Because active circuits can be placed underneath the OE antifuses, the present invention dramatically reduces chip size in comparison to conventional devices.Type: GrantFiled: April 16, 1998Date of Patent: May 2, 2000Assignee: Xilinx, Inc.Inventors: Kevin T. Look, Yakov Karpovich, Michael J. Hart
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Patent number: 6057180Abstract: Ultraviolet (UV) laser output (88) exploits the absorption characteristics of the materials from which an electrically conductive link (42), an underlying semiconductor substrate (50), and passivation layers (48 and 54) are made to effectively remove the link (42) without damaging the substrate (50). The UV laser output (88) forms smaller than conventional IR laser link-blowing spot diameters (58) because of its shorter wavelength, thus permitting the implementation of greater circuit density. A passivation layer positioned between the link and the substrate can be formulated to be sufficiently absorptive to UV laser energy and sufficiently thick to attenuate the laser energy to prevent it from damaging the substrate (50) in the laser beam spot area (43) in both the off-link and link-overlapped portions. The UV laser output (88) can be employed to controllably ablate a depthwise portion of the passivation layer (54) underlying the link (42) to facilitate complete removal of the link (42).Type: GrantFiled: June 5, 1998Date of Patent: May 2, 2000Assignee: Electro Scientific Industries, Inc.Inventors: Yunlong Sun, Edward J. Swenson
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Patent number: 6048739Abstract: A high density magnetic memory device and method of manufacture therefor, wherein the magnetic bit region is provided after selected higher temperature processing steps are performed. Illustrative higher temperature processing steps include those that are performed above for example 400.degree. C., any may include contact and via plug processing. The present invention may allow, for example, contact and via plug processing to be used to form magnetic RAM devices. As indicated above, contact and/or via plug processing typically allows the size of the contacts and vias to be reduced, and the packing density of the resulting memory device to be increased.Type: GrantFiled: December 18, 1997Date of Patent: April 11, 2000Assignee: Honeywell Inc.Inventors: Allan T. Hurst, Jeffrey S. Sather, William F. Witcraft, Cheisan J. Yue
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Patent number: 6033938Abstract: Treatment of the positive electrode interface of an antifuse provides significantly improved on-state reliability. Treatments include, but are not limited to, a plasma etch using carbon tetrafluoride (CF.sub.4), a sputter clean using Argon, and wet chemical treatments using dimethyl formamide (and water) or a resist developer.Type: GrantFiled: November 15, 1996Date of Patent: March 7, 2000Assignee: Xilinx, Inc.Inventors: Martin L. Voogel, Yakov Karpovich, Michael J. Hart
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Patent number: 6031275Abstract: The large voltage required to program a conventional antifuse is substantially reduced by forming the antifuse with a diffusion region and an overlying layer of silicide. The silicide layer is contacted at opposite ends so that a current can flow in through contacts at one end, and out through contacts at the opposite end. When unprogrammed, a voltage is applied to the semiconductor material in which the diffusion region is formed to prevent the diffusion region to semiconductor material from being forward biased. The antifuse is programmed by heating the silicide layer until the silicide layer agglomerates. The silicide layer can be heated by passing a current through the silicide layer.Type: GrantFiled: December 15, 1998Date of Patent: February 29, 2000Assignee: National Semiconductor CorporationInventors: Alexander Kalnitsky, Albert Bergemont, Pavel Poplevine
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Patent number: 5994170Abstract: The present invention is a method and apparatus for programming a stack of segments wherein each segment includes a plurality of die which are interconnected through metal interconnects patterned on the surface of each segment. Once the segments are arranged into a stack, the stack is connected to external circuits and each segment is addressed through control lines. Electrically conductive fuses on the segments are used as an interface between the control lines and the die. Segment level programming is performed on each segment by opening the conductive fuses on the segments in a predetermined pattern in order to route the control lines to each segment such that segments are uniquely addressed. After segment level programming, circuit board programming is performed so that any defective die found in the stack is logically replaced with replacement die in the stack.Type: GrantFiled: April 25, 1997Date of Patent: November 30, 1999Assignee: Cubic Memory, Inc.Inventors: David V. Pedersen, Michael G. Finley, Kenneth M. Sautter
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Patent number: 5989943Abstract: In one method for forming amorphous silicon antifuses with significantly reduced leakage current, a film of amorphous silicon is formed in a antifuse via between two electrodes. The amorphous silicon film is deposited using plasma enhanced chemical vapor deposition, preferably in an silane-argon environment and at a temperature between 200 and 500 degrees C., or reactively sputtered in a variety of reactive gases. In another method, an oxide layer is placed between two amorphous silicon film layers. In yet another method, one of the amorphous silicon film layers about the oxide layer is doped. In another embodiment, a layer of conductive, highly diffusible material is formed either on or under the amorphous silicon film. The feature size and thickness of the amorphous silicon film are selected to minimize further the leakage current while providing the desired programming voltage. A method also is described for for forming a field programmable gate array with antifuses.Type: GrantFiled: December 8, 1989Date of Patent: November 23, 1999Assignee: QuickLogic CorporationInventors: Ralph G. Whitten, Richard L. Bechtel, Mammen Thomas, Hua-Thye Chua, Andrew K. Chan, John M. Birkner
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Patent number: 5985698Abstract: A vertically oriented diode for use in delivering current to a multi-state memory element in a memory cell. A vertical diode may be disposed in a diode container extending downwardly from a top of a silicon or oxide layer, and may be formed of a combination of silicon and/or metal layers disposed proximate to inner surfaces of a diode container. A multi-state memory element may be formed of a multi-state material, such as a chalcogenide, above a diode to complete a memory cell.Type: GrantFiled: April 30, 1997Date of Patent: November 16, 1999Assignee: Micron Technology, Inc.Inventors: Fernando Gonzalez, Raymond A. Turi, Graham R. Wolstenholme, Charles L. Ingalls
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Patent number: 5970372Abstract: Antifuses are provided which include first and second conductive layers and an antifuse layer positioned between the first and second conductive layers. The antifuse layer includes at least one oxide layer positioned between two amorphous silicon layers. Interconnect structures and programmable logic devices are also provided which include the antifuses.Type: GrantFiled: December 30, 1997Date of Patent: October 19, 1999Assignee: Xilinx, Inc.Inventors: Michael J. Hart, Kevin T. Look, Yakov Karpovich
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Patent number: 5960263Abstract: A CMOS semiconductor device is programmed by a laser beam which causes a PN junction in a silicon substrate to be permanently altered. This produces a leakage path between a program node and a tank region in the substrate; the program node can be an input to a transistor in a CMOS circuit, for example, so this node will always hold the transistor on or off depending whether or not it has been laser-programmed. Preferably, the tank region is of opposite type compared to the substrate, so the program node is electrically isolated from the substrate in either case.Type: GrantFiled: June 2, 1993Date of Patent: September 28, 1999Assignee: Texas Instruments IncorporatedInventors: Kendall Scott Wills, Paul A. Rodriguez
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Patent number: 5937281Abstract: A method of fabricating an antifuse structure for field programmable gate array (FPGA) applications is described. First, a field oxide layer for isolation is grown on the semiconductor silicon substrate. Then, a bottom electrode, a thin dielectric layer and a first top electrode layer are sequentially deposited on the surface of the field oxide layer. Next, a photoresist layer is coated on the surface of the first top electrode layer. Then, the first top electrode layer is patterned to form a top electrode stud. Next, a layer of silicon dioxide (SiO.sub.2) is deposited by Liquid Phase Deposition (LPD) to improve the overall profile of the antifuse structure. Thereafter, the photoresist pattern is removed. Next, a second top electrode layer is deposited overlaying the LPD-SiO.sub.2 layer and the top electrode stud. The top electrode that consists of the second top electrode layer and the top electrode stud is completed. The antifuse structure of FPGAs is accomplished.Type: GrantFiled: August 5, 1997Date of Patent: August 10, 1999Assignee: Powerchip Semiconductor, Corp.Inventor: Shye-Lin Wu
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Patent number: 5923960Abstract: An integrated circuit includes a substrate with doped regions, a patterned polysilicon layer defining contacts and local interconnects, a submetal dielectric, a two-metal layer metal interconnect structure with an intermetal dielectric layer, and a passivation layer. Like the dielectric layers, the passivation layer is optically transparent, thick, and planarized. Because of this, laser energy can be directed through the passivation layer to fuse two conductors of the top metal layer without delaminating the passivation layer. In addition, laser energy is directed through the passivation layer and the intermetal dielectric to fuse pairs of conductors in the lower metal layer. Thus, the present invention provides for reliable convenient circuit modification without disturbing dielectric and exposing metal features to moisture and other contaminants.Type: GrantFiled: June 20, 1997Date of Patent: July 13, 1999Assignee: VLSI Technology, Inc.Inventor: Ian R. Harvey
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Patent number: 5920771Abstract: An improved antifuse which employs the base-emitter junction of a silicided single polysilicon bipolar transistor. The distance between the base metal and emitter metal is shortened and results from self aligning process steps rather than lithographic steps, resulting in a lower and better controlled programming voltage, programming energy and ON state resistance. Typically the conductive filament formed in the new antifuse is about 0.65 microns long and is formed by a voltage pulse having a relatively slow rise time (e.g. 150 microseconds), resulting in improved properties which provide advantages in circuit design and in manufacturing circuits using the new antifuse.Type: GrantFiled: March 17, 1997Date of Patent: July 6, 1999Assignee: Gennum CorporationInventors: Petrus T. Appelman, Andrew V. C. Cervin-Lawry, James D. Kendall, Efim Roubakha
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Patent number: 5915171Abstract: An antifuse structure for semiconductor programmable logic devices and the process of fabrication are described. The antifuse structure has its bottom electrically conductive layer featuring sharp corners formed by consumption of the polysilicon material into the sidewall in a thermal oxidation procedure. The sharp corners enhance the intensity of electric field established by a positive bias applied across the top and bottom conductive layers. The sharp corners do not enhance the electric field intensity when a negative bias is applied. This asymmetric conductivity assists in the reduction of the programming voltage as well as the increase of programming speed when the antifuse element is programmed.Type: GrantFiled: December 30, 1997Date of Patent: June 22, 1999Assignee: United Semiconductor Corp.Inventor: Yau-Kae Sheu
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Patent number: 5913137Abstract: A process electrostatic discharge ("ESD") protection device is incorporated on a chip with the antifuses that it is designed to protect and is formed as close in time as possible to the deposition of the antifuse material layer (the layer being protected) so that ESD protection is available at all practical stages of processing. According to a first aspect of the invention, an ESD protection device is formed by exposing edges of an antifuse bottom electrode during the antifuse cell open mask/etch step. It is biased on during processing. A sharp corner of the electrode and a deep aspect ratio provide degrade antifuse performance for the protection cell (resulting in reduced breakdown voltage and increased leakage current) and, as designed, the protection cell will rupture before other cells because it has a lower breakdown voltage. Once the protection cell ruptures, it will continue to conduct and protect other antifuses from ESD damage.Type: GrantFiled: October 1, 1996Date of Patent: June 15, 1999Assignee: Actel CorporationInventor: Wenn-Jei Chen
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Patent number: 5913138Abstract: The present invention relates to the method of manufacturing an antifuse element having an antifuse layer formed between interconnection layers. Conventionally, an antifuse layer was formed after an aperture was formed through an interlayer insulating film. Such resulted in a thinner film thickness at the corner formed by inner wall surface of the aperture and a lower electrode layer. As it is very difficult to control the film thickness of the thinnest part to a specific value, control of the insulation breakdown voltage in "off" state was difficult. The present antifuse element includes a layer with a flat shape of an even thickness. The layer is a complexed film of amorphous silicon film, silicon nitride film and silicon oxide film. The antifuse electrode layer is of a titanium nitride, the film thickness of which is thicker than the invasion length of a fuse link into electrode layers.Type: GrantFiled: February 26, 1997Date of Patent: June 15, 1999Assignee: Matsushita Electronics CorporationInventors: Toru Yamaoka, Hiroshi Sakurai, Hirotsugu Honda, Hiroshi Yuasa
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Patent number: 5904507Abstract: Disclosed is a method of fabricating a programmable antifuse structure wherein programming of the antifuse structure results in conducting paths which are confined within a finite predictable area. The method includes depositing an insulating layer over a field. Additionally, the method includes creating a via through a via area of the insulating layer to expose a programmable surface area of the field. The method also includes depositing an interlayer over the exposed programmable surface of the field, over sidewalls of the via, and over an extended surface region of the insulating layer, the extended surface region including the via area. The method includes depositing a first conducting layer over the interlayer. The method also includes etching in the extended surface region to the insulating layer; the etching is for confining formation of conductive paths to within the via area upon programming of the programmable antifuse structure.Type: GrantFiled: February 23, 1998Date of Patent: May 18, 1999Assignee: National Semiconductor CorporationInventor: Michael E. Thomas
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Patent number: 5899707Abstract: An antifuse structure and method for making the antifuse structure having a doped antifuse layer is disclosed. The doped antifuse layer is preferably deposited over a lower electrode. A barrier layer may then be formed over the doped antifuse layer and an upper electrode may subsequently be deposited over the barrier layer. The method of depositing the doped antifuse layer includes: (a) providing a chemical vapor deposition reactor having a support chuck for supporting a partially fabricated silicon wafer; (b) powering up the chemical vapor deposition reactor and heating the partially fabricated silicon wafer; (c) selecting a dopant species for the antifuse layer (e.g, n-type or p-type); (d) introducing a gaseous mixture of a silane compound and the selected dopant species into the chemical vapor deposition reactor with the aid of a neutral species; and (e) depositing the antifuse layer over the lower electrode.Type: GrantFiled: August 20, 1996Date of Patent: May 4, 1999Assignee: VLSI Technology, Inc.Inventors: Ivan Sanchez, Landon B. Vines
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Patent number: 5882997Abstract: A resistive load structure and method for making a resistive load structure for an integrated circuit includes the use of an amorphous silicon "antifuse" material. The resistive load structure can be used in an SRAM cell to provide a load to counteract charge leakage at the drains of two pull-down transistors and two pass transistors of the SRAM cell. The resistive load structure is advantageously formed by depositing an amorphous silicon pad over a conductive via, and the resistance of the resistive load structure is controlled by adjusting the thickness of the amorphous silicon pad and varying the diameter of the underlying conductive via.Type: GrantFiled: October 21, 1997Date of Patent: March 16, 1999Assignee: VLSI Technology, Inc.Inventors: Harlan Lee Sur, Jr., Subhas Bothra
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Patent number: 5880016Abstract: Adjusting elements (R1, R2 and R3) are redundantly or preliminarily built in an IC circuit body (5), the adjusting elements (R1, R2 and R3) are connected to one another through conductor patterns (P1, P2 and P3) provided outside the circuit body (5), and after the circuit operating function is confirmed by inspection, the conductor patterns (P1, P2 and P3) are selectively cut to select an adjusting element to be used, thereby to adjust or select a function of the circuit body.Type: GrantFiled: October 30, 1997Date of Patent: March 9, 1999Assignee: Mitsumi Electric Co., Ltd.Inventors: Ryuichi Sada, Shigemitsu Watanabe
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Patent number: 5861325Abstract: A method for providing a conductive link between conductive materials, e.g., metals, separated by a non-conductive material, e.g., a silicon based glass material. In a preferred embodiment a single pulse of laser energy is applied to at least one of the conductive materials to produce mechanical strain therein which strain initiates a fracturing of the non-conductive material so as to provide at least one fissure therein extending between the conductive materials. The laser energy pulse further causes at least one of the conductive materials to flow in such fissure to provide a conductive link between the conductive materials.Type: GrantFiled: March 10, 1994Date of Patent: January 19, 1999Assignee: Massachusetts Institute of TechnologyInventor: Joseph B. Bernstein
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Patent number: 5861328Abstract: A method of fabricating GMR devices on a CMOS substrate structure with a semiconductor device formed therein. The method includes forming a dielectric system with a planar surface having a roughness in a range of 1 .ANG. to 20 .ANG. RMS on the substrate; disposing and patterning films of giant magneto-resistive material on the planar surface so as to form a memory cell; disposing a dielectric cap on the cell so as to seal the cell and provide a barrier to subsequent operations; forming vias through the dielectric cap and the dielectric system to interconnects of the semiconductor device; forming vias through the dielectric cap to the magnetic memory cell; and depositing a metal system through the vias to the interconnects and to the memory cell.Type: GrantFiled: October 7, 1996Date of Patent: January 19, 1999Assignee: Motorola, Inc.Inventors: Saied N. Tehrani, Eugene Chen, Mark Durlam, Xiaodong T. Zhu, Clarence J. Tracy
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Patent number: 5856233Abstract: A method is provided for forming a field programmable device of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A first conductive layer is formed. A first, fusible, dielectric layer is formed over the first conductive layer. The dielectric layer is patterned and etched to form a plurality of dielectric regions exposing portions of the first conductive layer. A second dielectric layer is then formed over the dielectric regions and the exposed portions of the first conductive layer. A plurality of contact openings through the second dielectric layer are formed to expose portions of the first conductive layer and portions of the dielectric regions. A second conductive layer is then formed over the second dielectric layer and in the contact openings.Type: GrantFiled: May 3, 1995Date of Patent: January 5, 1999Assignee: STMicroelectronics, Inc.Inventors: Frank Randolph Bryant, Fusen E. Chen, Girish Anant Dixit
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Patent number: 5856213Abstract: An antifuse structure is formed between two metal contacts in which a thin oxide layer is formed on the first or bottom metal, a shallow via is provided oxide layer and a layer of amorphous silicon is deposited over the thin oxide and into the shallow via without leaving the usual furrows in the amorphous silicon and thereby eliminating the step coverage problems of cusps forming in the subsequently applied second or top metal.Type: GrantFiled: July 25, 1996Date of Patent: January 5, 1999Assignee: VLSI Technology, Inc.Inventors: Michela S. Love, Delbert H. Parks
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Patent number: 5821160Abstract: A method for manufacturing an static random access memory (SRAM) cell (10) begins by manufacturing a fuse region (36) over a substrate (10). An etch stop layer (44) is formed overlying the fuse region (36) from resistor polysilicon material. In order for the fuse region (36) to be accessed and properly disabled, an opening (60) must be provided which stops on the etch stop layer (44). The etch stop (44) ensures a consistent and repeatable optimal thickness X of dielectric material above the fuse region (36) to provide for proper laser access and repair. The etch stop layer (44) therefore reduces wafer to wafer and die to die variation in thickness X and provides for a higher yield laser repair for each SRAM integrated circuit and every wafer processed using this methodology.Type: GrantFiled: June 6, 1996Date of Patent: October 13, 1998Assignee: Motorola, Inc.Inventors: Robert A. Rodriguez, Douglas J. Dopp, Robert E. Booth, Jr.
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Patent number: 5807786Abstract: A method for forming an antifuse interconnect structure, for a one-time fusible link, to be used with field-programmable gate arrays, has been developed. The process features the use of an amorphous silicon layer, used as the antifuse layer, with the amorphous silicon layer protected by a thin barrier layer, during the patterning procedure. The protected antifuse layer results in a reproducible thickness, and thus reproducible pulsing voltages, needed for rupturing of the antifuse layer. Planarization of an underlying metal plug, via an insulator refill procedure, offers a smooth surface for the overlying antifuse layer.Type: GrantFiled: July 30, 1997Date of Patent: September 15, 1998Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventor: Tzong-Sheng Chang
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Patent number: 5793094Abstract: A method for substantially reducing variations in a programming voltage of an anti-fuse structure formed on an integrated circuit wafer. The anti-fuse structure has a metal-one layer, an anti-fuse layer disposed above the metal-one layer, a oxide layer disposed above the anti-fuse layer, and a via hole in the oxide layer through to the anti-fuse layer for receiving a deposition of a metal-two material. The method includes the step of rendering a selected anti-fuse area susceptible to fuse link formation by reducing a resistivity of the selected anti-fuse area to diffusion of atoms from one of the metal-one layer and the metal-two layer when a programming voltage is applied between the metal one layer and the metal two layer. The selected anti-fuse area is located in the anti-fuse layer and substantially adjacent to and outside of an anti-fuse area directly below the via hole. The method further includes the step of depositing the metal-two material into the via hole.Type: GrantFiled: December 28, 1995Date of Patent: August 11, 1998Assignee: VLSI Technology, Inc.Inventors: Ivan Sanchez, Yu-Pin Han, Ying-Tsong Loh, Walter D. Parmantie
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Patent number: 5793095Abstract: An integrated circuit includes a substrate with doped regions, a patterned polysilicon layer defining contacts and local interconnects, a submetal dielectric, a two-metal layer metal interconnect structure with an intermetal dielectric layer, and a passivation layer. Like the dielectric layers, the passivation layer is optically transparent, thick, and planarized. Because of this, laser energy can be directed through the passivation layer to fuse two conductors of the top metal layer without delaminating the passivation layer. In addition, laser energy is directed through the passivation layer and the intermetal dielectric to fuse pairs of conductors in the lower metal layer. Thus, the present invention provides for reliable convenient circuit modification without disturbing dielectric and exposing metal features to moisture and other contaminants.Type: GrantFiled: August 21, 1996Date of Patent: August 11, 1998Assignee: VLSI Technology, Inc.Inventor: Ian R. Harvey
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Patent number: 5786240Abstract: An over-etched (OE) antifuse includes a lower electrode, an antifuse layer contacting the lower electrode by an over-etched via, and a second conductive layer formed on the antifuse layer. This over-etched via forms a trench in the lower electrode, wherein in one embodiment the depth of the trench approximates the thickness of the antifuse layer. The trench narrows the programming voltage distribution of the antifuses on the device, irrespective of topology. Because active circuits can be placed underneath the OE antifuses, the present invention dramatically reduces chip size in comparison to conventional devices.Type: GrantFiled: June 27, 1996Date of Patent: July 28, 1998Assignee: Xilinx, Inc.Inventors: Kevin T. Look, Yakov Karpovich, Michael J. Hart
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Patent number: 5786268Abstract: Antifuses and gate arrays with antifuses are disclosed that have high thermal stability, reduced size, reduced leakage current, reduced capacitance in the unprogrammed state, improved manufacturing yield, and more controllable electrical characteristics. Some antifuses include spacers in the antifuse via. In some antifuses, the programmable material is planar, and the top or the bottom electrode is formed in the antifuse via. In some gate arrays, the antifuses are formed above the dielectric separating two levels of routing channels rather than below that dielectric.Type: GrantFiled: August 1, 1997Date of Patent: July 28, 1998Assignee: QuickLogic CorporationInventors: Kathryn E. Gordon, Richard J. Wong
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Patent number: 5783467Abstract: An antifuse structure includes a first electrode, a layer of enhanced amorphous silicon over the first electrode, and a second electrode over the layer of enhanced amorphous silicon. The layer of enhanced amorphous silicon is formed by an ion-implantation of a neutral species and a dopant species into a deposited layer of amorphous silicon, such that the antifuse structure will have a stable conductive link in a programmed state and such that it will be less susceptible to off-state leakage in an unprogrammed state. A method for making an antifuse structure includes forming a lower electrode, depositing an amorphous silicon layer over the lower electrode, ion-implanting a neutral species and a dopant species into the amorphous silicon layer, and forming an upper electrode over the amorphous silicon layer.Type: GrantFiled: December 29, 1995Date of Patent: July 21, 1998Assignee: VLSI Technology, Inc.Inventors: Yu-Pin Han, Ying-Tsong Loh, Ivan Sanchez
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Patent number: 5780323Abstract: According to a first aspect of the present invention an antifuse structure capable of high density fabrication comprises an antifuse material layer under a plug of an electrically conductive material disposed between two metallization layers. According to a second aspect of the present invention an antifuse structure capable of high density fabrication comprises an antifuse material layer comprising a first nitride/first amorphous silicon/second nitride/second amorphous silicon sandwich under a plug of an electrically conductive material lined with titanium disposed between two metallization layers. In this aspect of the invention the titanium is allowed to react with the second amorphous silicon layer to form an electrically conductive silicide. This leaves the first nitride/first amorphous silicon/second nitride as the antifuse material layer while guaranteeing a strict control on the thickness of the antifuse material layer for assuring strict control over its respective breakdown or programming voltage.Type: GrantFiled: November 12, 1996Date of Patent: July 14, 1998Assignee: Actel CorporationInventors: Abdul R. Forouhi, Frank W. Hawley, John L. McCollum, Yeouchung Yen
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Patent number: 5763299Abstract: An antifuse includes an antifuse material disposed between a lower conductive electrode and an upper conductive electrode. The antifuse material includes a layer of amorphous silicon disposed between two layers of silicon nitride. A thin layer of silicon dioxide is disposed between the layer of amorphous silicon and one of the silicon nitride layers.Type: GrantFiled: March 12, 1996Date of Patent: June 9, 1998Assignee: Actel CorporationInventors: John L. McCollum, Frank W. Hawley
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Patent number: 5759876Abstract: An antifuse includes a metal cap layer located at the second barrier layer of the antifuse to improve the antifuse yield and long term reliability. An antifuse further includes one or more interfacial oxide film layers surrounding an antifuse dielectric layer to provide narrowing of the antifuse programming voltage distribution and to further improve the antifuse yield and long term reliability.Type: GrantFiled: November 1, 1995Date of Patent: June 2, 1998Assignee: United Technologies CorporationInventors: Scott G. Singlevich, Bradley S. Holway, Kurt D. Humphrey, Brian Scott Poarch, Michael R. Reeder, Neal J. Verzwyvelt
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Patent number: 5756393Abstract: A method of jointly forming stacked capacitors and antifuses includes, a) providing a common layer of electrically conductive material to form both a capacitor storage node and an inner antifuse plate; b) providing a common layer of dielectric material over the capacitor storage node and the inner antifuse plate, the common layer of dielectric material comprising both an intervening capacitor dielectric element and an intervening antifuse dielectric element, the common layer of dielectric material having a first breakdown voltage per unit length value for a given current per unit area; c) providing a common layer of electrically conductive material over the common layer of dielectric material to form both a capacitor cell layer and an outer antifuse plate; d) providing a lateral edge of the outer antifuse plate and a lateral edge of the intervening antifuse dielectric element; and e) depositing an antifuse breakdown layer of dielectric material over the lateral edges of the outer antifuse plate and the intervType: GrantFiled: March 21, 1997Date of Patent: May 26, 1998Assignee: Micron Technology, Inc.Inventor: Charles H. Dennison
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Patent number: 5753540Abstract: Disclosed is a method for programming an antifuse structure. The antifuse structure is programmed by applying an alternating current having alternating current pulses between a bottom and a top electrode to generate a conduction path through an antifuse material sandwiched between the electrodes. The conduction path is formed incrementally due to an electron flow produced as a result of each alternating current pulse thereby defining the conduction path at a substantially centered portion of the antifuse material.Type: GrantFiled: August 20, 1996Date of Patent: May 19, 1998Assignee: VLSI Technology, Inc.Inventors: Koucheng Wu, Ivan Sanchez, Yu-Pin Han, Ying-Tsong Loh
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Patent number: 5742555Abstract: An integrated circuit anti-fuse is described which is fabricated as a capacitor using a layer of oxide. The two plates of the anti-fuse are coupled to appropriate voltage levels to rupture the oxide and form a conductive short between the plates. One of the plates is formed as a diffused well which is coupled to an external voltage during programming. The well is biased to an internal voltage during normal operation of the circuit incorporating the anti-fuse.Type: GrantFiled: August 20, 1996Date of Patent: April 21, 1998Assignee: Micron Technology, Inc.Inventors: Kenneth W. Marr, Shubneesh Batra
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Patent number: 5714416Abstract: A semiconductor device used as a semiconductor memory device is disclosed which is made of an amorphous silicon material that provides either a "1" or "0" memory state when the amorphous silicon material is in a non-conduction or insulating state and a "0" or "1" memory state when the amorphous silicon material is transformed, by use of a breakdown voltage applied to electrodes coupled thereto, into a conducting state. The amorphous silicon material is located adjacent to a doped semiconductor region of a semiconductor substrate separated only by a relatively thin primarily metal ohmic contact. The resulting semiconductor structure for the semiconductor device or semiconductor memory device is primarily a single level metalization type structure. A write-once, read-only semiconductor memory array is also disclosed which uses, as each memory cell of the array, one of the disclosed semiconductor memory devices.Type: GrantFiled: April 28, 1995Date of Patent: February 3, 1998Assignee: Microchip Technology IncorporatedInventors: Eric C. Eichman, Thomas C. Salt
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Patent number: 4601916Abstract: An economical process for producing metal plated through holes in metal core circuit boards which permits the formation of small holes and fine conductor lines is disclosed. A metal sheet, which will become the core of a metal core circuit board, is provided with insulation layers on both sides, and through holes are provided through the insulation layers. The process involves incorporating fillers in a resinous coating solution which is electrophoretically applied to the hole walls to form an insulating layer of uniform thickness thereon. An increased diameter in the metal wall portion of each hole acts to restrict flow of the filled resinous coating solution during cure resulting in a straight hole wall. The coating is adhesion promoted and a metal layer is deposited thereon.Type: GrantFiled: July 18, 1984Date of Patent: July 22, 1986Assignee: Kollmorgen Technologies CorporationInventor: James J. Arachtingi