Electromigration Resistant Metallization Patents (Class 438/927)
  • Patent number: 6057238
    Abstract: An aluminum-containing film having an oxygen content within the film. The aluminum-containing film is formed by introducing hydrogen gas and oxygen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: May 2, 2000
    Assignee: Micron Technology, Inc.
    Inventors: Kanwal K. Raina, David H. Wells
  • Patent number: 5993908
    Abstract: A method of producing an aluminum film on a substrate, from which very narrow aluminum conductor tracks can be created that are highly resistant to electromigration and/or stress migration. The substrate with the polycrystalline aluminum film is cooled in an oven in a controlled fashion from a target temperature to a final temperature such that energetically stable Al.sub.2 Cu-.theta.-phases are formed directly among the individual aluminum grains in the aluminum film. The cooling is controlled such that the instantaneous temperature passes through a predetermined temperature profile. Within the range of 320.degree. C. to 200.degree. C., the cooling gradient is less than 6.degree. C. per hour.
    Type: Grant
    Filed: May 28, 1997
    Date of Patent: November 30, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Manfred Schneegans, Stefan Dietrich, Alexander Hirsch
  • Patent number: 5981378
    Abstract: Disclosed is an aluminum filled via hole for use in a semiconductor interconnect structure. The aluminum filled via hole of the semiconductor interconnect structure includes a first patterned metallization layer lying over a first dielectric layer. A second dielectric layer overlying the first patterned metallization layer and the first dielectric layer. An aluminum filled via hole defined through the second dielectric layer and in contact with the first patterned metallization layer. The aluminum filled via hole has an electromigration barrier cap over a topmost portion of the aluminum filled via hole that is substantially level with the second dielectric layer. The electromigration barrier cap having a thickness of between about 500 angstroms and about 2,500 angstroms.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: November 9, 1999
    Assignee: VLSI Technology, Inc.
    Inventor: Subhas Bothra
  • Patent number: 5963831
    Abstract: A method of fabricating an interconnect structure having improved electromigration resistance. Two conductive lines are formed over a substrate and isolated by a dielectric layer. A contact/via array including a plurality of row contact/vias and column contact/vias are formed within the dielectric layer and electrically connect to the two conductive lines. The load resistors are respectively inserted into the two conductive lines close to the contact/via array. The load resistors are parallel to each other and disposed to its corresponding contact/via array. The load resistors having various resistances are formed by a plurality of slots with various lengths, which are filled with dielectrics. Accordingly, the current paths from one conductive line to the other conductive line through the contact/vias and the load resistors corresponding to the two conductive lines have identical equivalent resistance.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: October 5, 1999
    Assignee: United Microelectronics Corp.
    Inventor: Kuan-Yu Fu
  • Patent number: 5963729
    Abstract: An automated method detects electromigration violations in an integrated circuit design. Starting from the lowest hierarchy of the design so far completed, the parasitic (resistance and capacitance) component values extracted from a layout file are propagated up. Then, at the top-most level, lumping algorithms are employed to calculate the parasitic values for all of the top-most level nets. These values are then passed back down to the lower levels and then at each level, the layout is checked using previously computed parasitic values and EM limits. A peak current, AC-average current and AC-rms current are calculated for every layout, and then compared with the process EM rules for violations, in which the optimum line width and number of vias are specified for each interconnection.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: October 5, 1999
    Assignee: Sun Microsystems Inc.
    Inventors: Sandeep A. Aji, Manjunath Doreswamy, Georgios Konstadinidis
  • Patent number: 5959360
    Abstract: A structure of a conductive line. The structure of a conductive line comprises a substrate with two conductive lines formed thereon. These two conductive lines are isolated by the formation of a dielectric layer. The conductive lines are electrically connected by a contact/via array. The contact/via array further comprises contact/via columns and contact/via rows made up of contacts/vias. Each contact/via column and contact/via row are added with a load resistor, so that the equivalent resistance of each contact/via is identical.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: September 28, 1999
    Assignee: United Microelectronics Corp.
    Inventor: Kuan-Yu Fu
  • Patent number: 5930587
    Abstract: A method for accurately and objectively evaluating stress migration effects on long term reliability of integrated circuits. A sample containing a conductive runner is fabricated according to a given fabrication process. The fabricated sample undergoes a heating step at a first temperature for a first time period to induce material interactions at an accelerated rate, followed by cooling the sample to a second temperature and maintaining the second temperature for a time of sufficient duration such that relaxation occurs. Then the sample undergoes a heating process at a third temperature for a time sufficient to nucleate a predetermined number of voids, followed by heating the sample runner at a fourth temperature, less than than the third temperature, to propagate the voids such that a maximum void size is determined. Void distribution is preferably monitored by optical and scanning electron microscopy.
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: July 27, 1999
    Assignee: Lucent Technologies
    Inventor: Vivian W. Ryan
  • Patent number: 5913145
    Abstract: In order to provide a thermally stable diffusion barrier for a contact, a layer of titanium is formed on the patterned substrate. A layer of tungsten nitride is formed on the titanium layer. After an annealing step, an interfacial layer and a layer of titanium nitride are formed between the substrate and a tungsten layer. These layers provide a diffusion barrier which is more thermally stable than a titanium nitride layer applied directly on the substrate and permits the formation of a contact structures that can withstand subsequent high temperature steps.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: June 15, 1999
    Assignee: Texas Instruments Incorporated
    Inventors: Jiong-Ping Lu, Chih-Chen Cho
  • Patent number: 5891802
    Abstract: There is provided an improved metallization stack structure and a method for fabricating the same so as to produce a higher electromigration resistance and yet maintain a relatively low resistivity. The metallization stack structure includes a pure copper layer sandwiched between a top thin doped copper layer and a bottom thin doped copper layer. The top and bottom thin doped copper layers produce a higher electromigration resistance. The pure copper layer produces a relatively low resistivity.
    Type: Grant
    Filed: July 23, 1997
    Date of Patent: April 6, 1999
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Jiang Tao, Peng Fang
  • Patent number: 5736460
    Abstract: In a semiconductor device having gold interconnections for connecting elements formed on a substrate with each other, the improvement is that the average dimension of gold grains constituting the gold interconnections is determined to be 0.17 through 0.25 times as large as width of the gold interconnections. In addition, the average dimension of the gold grains is determined so that the mean time to failure is not less than a predetermined period of time.
    Type: Grant
    Filed: June 11, 1997
    Date of Patent: April 7, 1998
    Assignee: NEC Corporation
    Inventor: Hirosi Kato
  • Patent number: 5633198
    Abstract: A new method of metallization using a new design of metal contact shape, contact/via profile, and metal lines having considerably reduced current density and improved electromigration of metal lines is achieved. Metal contacts are formed in a rectangular shape instead of a square shape with the wider side perpendicular to the current direction. Contact openings are made having concavo-concave profiles which can provide a wider conducting cross-sectional area than can conventional openings with a vertical profile near the contact bottom. Gaps are formed within wide and high current metal lines so that current density can be effectively lowered by utilizing the whole metal line uniformly.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: May 27, 1997
    Assignee: United Microelectronics Corporation
    Inventors: Water Lur, Jiun Y. Wu
  • Patent number: 5633197
    Abstract: A new method of metallization using a new design of metal contact shape, contact/via profile, and metal lines having considerably reduced current density and improved electromigration of metal lines is achieved. Metal contacts are formed in a rectangular shape instead of a square shape with the wider side perpendicular to the current direction. Contact openings are made having concavo-concave profiles which can provide a wider conducting cross-sectional area than can conventional openings with a vertical profile near the contact bottom. Gaps are formed within wide and high current metal lines so that current density can be effectively lowered by utilizing the whole metal line uniformly.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: May 27, 1997
    Assignee: United Microelectronics Corporation
    Inventors: Water Lur, Jiun Y. Wu
  • Patent number: 5627101
    Abstract: A polysilicon sensor is described which can be incorporated onto a silicon wafer containing integrated circuits for the purpose of detecting and monitoring electromigration(EM) in metal test stripes representative of the interconnection metallurgy used by the integrated circuits. The sensor capitalizes on the property of silicon whereby a small increase in temperature causes a large increase in carrier concentration. In this regard, the local temperature rise of an adjacent metal line undergoing EM failure manifests itself as a decrease in resistance of the sensor. The sensor is particularly suited for testing multi-level metallurgies such as those having an aluminum alloy sandwiched between metallic layers such as those used for diffusion barriers and anti-reflective coatings. Its fabrication is compatible with conventional MOSFET processes which use a self-aligned polysilicon gate.
    Type: Grant
    Filed: December 4, 1995
    Date of Patent: May 6, 1997
    Assignee: Taiwan Semiconductor Manufacturing Company Ltd.
    Inventors: Chih-Sheng Lin, Shun-Yi Lee