Patents by Inventor Chris C. Yu

Chris C. Yu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5531861
    Abstract: A chemical-mechanical-polishing process in which energy is imparted to a polishing pad (18) dislodging particles (46), which are removed by vacuum withdrawal to continuously clean the surface of the polishing pad (14). Energy is imparted to polishing pad (18) by either sonic energy from acoustic waves, or by physical impaction. The acoustic waves are generated by submerging a transducer (28) in the polishing slurry (18). The transducer (28) is powered by a voltage amplifier (30) coupled to a computer controlled-frequency generator (32). The acoustic wave frequency is adjusted by the frequency generator (32) to induce sonic vibration in the polishing pad (14) such that particles (46) are continuously dislodged from polishing pad (14). Physical impaction is performed by an impaction tool (48) coupled to a vacuum head (33).
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: July 2, 1996
    Assignee: Motorola, Inc.
    Inventors: Chris C. Yu, Tat-Kwan Yu
  • Patent number: 5525191
    Abstract: The selection of pH, the polishing slurry, and types of polishing particles within a polishing slurry are chosen, so that polishing product is capable of coating onto the polishing particles. More specifically, the pH of the polishing slurry is selected to be between the iso-electric points of the polishing product and the particles within the polishing slurry. More than one type of material may be used within a polishing slurry. Particles of one material may do most of the polishing, while the particles of the other material become coated with polishing product and aid in transporting it away from the substrate.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: June 11, 1996
    Assignee: Motorola, Inc.
    Inventors: Papu D. Maniar, Chris C. Yu
  • Patent number: 5441598
    Abstract: A mold is used to form a polishing pad, wherein the surface of the polishing side of the polishing pad is determined by a primary surface of the mold. Features along the polishing side of a polishing pad may take any one of several different shapes. Channels along the polishing side of the polishing pad allow a smaller pore size to be used. The mold allows more control over the surface of the polishing side, which in turn give more control over polishing characteristics.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 15, 1995
    Assignee: Motorola, Inc.
    Inventors: Tat-Kwan Yu, Chris C. Yu
  • Patent number: 5435772
    Abstract: The present invention includes a polishing pad to improve polishing uniformity across a semiconductor substrate and a method using the polishing pad. The polishing pad has a first region that is closer to the edge of the polishing pad and a second region adjacent to the first region and further from the edge of the polishing pad. The polishing pad is configured, so that the second region is thicker or less compressible compared to the first region. The polishing pad should not require significantly changing any of the equipment. Oscillating range and possibly polishing pressure may need to be changed when one of the polishing pads of the present invention is used. Other operational parameters are not expected to be substantially different from a conventional polishing pad, although slight optimization of the other operating parameters may be needed.
    Type: Grant
    Filed: April 30, 1993
    Date of Patent: July 25, 1995
    Assignee: Motorola, Inc.
    Inventor: Chris C. Yu
  • Patent number: 5399234
    Abstract: A chemical-mechanical-polishing process in which acoustic waves are generated in the polishing slurry (18) to enable detection of an end-point in the polishing process, and to continuously clean the surface of a polishing pad (14) in a polishing apparatus (10). Acoustic waves are generated in the polishing slurry (18) by submerging a transducer (28) in the polishing slurry (18). The transducer (28) is powered by a voltage amplifier (30) coupled to a frequency generator (32). The frequency of the acoustic waves is adjusted by the frequency generator (32) to obtain optimum wave generation in the polishing slurry (18). The end-point of the polishing process is detected by a change in the acoustic wave velocity in the polishing slurry (18), which occurs when the slurry composition changes at end-point. The wave velocity is monitored by a receiver (34) submerged in the polishing slurry (18) at a predetermined distance from the transducer (28).
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: March 21, 1995
    Assignee: Motorola Inc.
    Inventors: Chris C. Yu, Tat-Kwan Yu, Jeffrey L. Klein
  • Patent number: 5354490
    Abstract: A semiconductor processing method of chemical mechanical polishing a predominately copper containing metal layer on a semiconductor substrate includes, a) providing a chemical mechanical polishing slurry comprising H.sub.2 0, a solid abrasive material, and a third component selected from the group consisting of HNO.sub.3, H.sub.2 SO.sub.4, and AgNO.sub.3 or mixtures thereof; and b) chemical mechanical polishing a predominately copper containing metal layer on a semiconductor substrate with the slurry. Such slurry also constitutes part of the invention. Such slurry may also contain an additional oxidant selected from the group consisting of H.sub.2 0.sub.2, HOCl, KOCl, KMnO.sub.4 and CH.sub.3 COOH or mixtures thereof to form a copper oxide passivating-type layer at the copper surface.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: October 11, 1994
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Trung T. Doan
  • Patent number: 5329734
    Abstract: The present invention includes a polishing pad to improve polishing uniformity across a substrate and a method using the polishing pad. The polishing pad has a first region that lies closer to the edge of the polishing pad and a second region that lies further from the edge of the polishing pad. The second region has a plurality of openings or a larger average pore size compared to the first region. Each opening or the average pore size of the second region may be 1) between about 250-1000 microns or 2) in a range of about 25-1000 percent larger than the average pore size of the first region. The polishing pad may be used in a chemical-mechanical polishing without having to substantially changing the polisher or the operational parameters of the polisher other than the oscillating range.
    Type: Grant
    Filed: April 30, 1993
    Date of Patent: July 19, 1994
    Assignee: Motorola, Inc.
    Inventor: Chris C. Yu
  • Patent number: 5314843
    Abstract: A semiconductor wafer has a surface layer to be planarized in a chemical mechanical polishing (CMP) process. An area of the layer that is higher than another area is altered so that the removal rate is higher. For example, if the surface layer is TEOS oxide, the higher layer may be bombarded with boron and phosphorus to produce BPSG, which has a polishing rate 2-3 times that of the TEOS. Upon CMP planarization, the higher area erodes faster resulting in improved planarization. Alternatively, the lower area may be doped with nitrogen to produce a nitride which is more resistant to CMP, with the same result. Likewise areas, such as tungsten troughs, which tend to be dished by CMP, may be changed to WNx which is more resistant to the tungsten CMP than the adjacent tungsten, eliminating the dishing upon planarization.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: May 24, 1994
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Gurtej S. Sandhu, Trung T. Doan
  • Patent number: 5300155
    Abstract: An IC chemical mechanical planarization (cmp) process incorporating slurry temperature control. Specifically, there is a VCMP process which requires small holders 18. The VCMP process incorporates small quantities of chemicals in the holder, and utilizes a system of closely regulating the heating and cooling of the chemical component of the VCMP process to increase and decrease the chemical reaction, and therefore the speed of the chemical removal of tungsten material.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: April 5, 1994
    Assignee: Micron Semiconductor, Inc.
    Inventors: Gurtej S. Sandhu, Chris C. Yu
  • Patent number: 5270263
    Abstract: A process for depositing a thin film of aluminum nitride (AlN) includes sputtering an aluminum target with energetic nitrogen ions generated in a nitrogen plasma. A single gas (i.e. nitrogen) is used as both the reactive gas and as the sputtering gas. The process is especially adapted for forming an etchstop layer for use in forming contact vias through a dielectric layer in semiconductor manufacture. The process is also useful in semiconductor manufacture for forming an aluminum nitride (AlN) film that may be used as a passivation layer, as a ceramic packaging material, as a mask for ion implantation, as a substrate material in hybrid circuits, and as a high bandgap window for GaAs solar cells.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: December 14, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Sung C. Kim, Chris C. Yu, Trung T. Doan
  • Patent number: 5244534
    Abstract: A method for forming conductive plugs within an insulation material is described. The inventive process results in a plug of a material such as tungsten which is more even with the insulation layer surface than conventional plug formation techniques. Conventional processes result in recessed plugs which are not easily or reliably coupled with subsequent layers of sputtered aluminum or other conductors. The inventive process uses a two-step chemical mechanical planarization technique. An insulation layer with contact holes is formed, and a metal layer is formed thereover. A polishing pad rotates against the wafer surface while a slurry selective to the metal removes the metal overlying the wafer surface, and also recesses the metal within the contact holes due to the chemical nature and fibrous element of the polishing pad. A second CMP step uses a slurry having an acid or base selective to the insulation material to remove the insulator from around the metal.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: September 14, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Trung T. Doan
  • Patent number: 5240552
    Abstract: A method and apparatus for chemically mechanically planarizing (CMP) a semiconductor wafer includes directing acoustic waves at the wafer and receiving reflected acoustic waves from the wafer during the (CMP) process. By analyzing the acoustic waves and reflected acoustic waves a thickness of the wafer can be determined and an endpoint and thickness of films formed on the wafer can be monitored in real time during the (CMP) process. The process parameters of the (CMP) process can then be adjusted as required to improve the uniformity of the process.
    Type: Grant
    Filed: December 11, 1991
    Date of Patent: August 31, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Gurtej S. Sandhu
  • Patent number: 5232549
    Abstract: Fabrication of spacer supports for use in flat panel displays through a process which involves 1) depositing an insulating material on an electrode plate, 2) optionally, patterning a reflective material superjacent the insulating material, 3) irradiating the electrode plate, and thereby removing the exposed insulating material, 4) optionally, removing the reflective material, and thereby exposing the remaining insulative material which will serve as the spacer supports, after which the plate can be aligned with a complementary electrode plate, and a vacuum formed therebetween.
    Type: Grant
    Filed: April 14, 1992
    Date of Patent: August 3, 1993
    Assignee: Micron Technology, Inc.
    Inventors: David A. Cathey, Chris C. Yu, Trung T. Doan, Tyler A. Lowrey, J. Brett Rolfson
  • Patent number: 5225034
    Abstract: A semiconductor processing method of chemical mechanical polishing a predominately copper containing metal layer on a semiconductor substrate includes, a) providing a chemical mechanical polishing slurry comprising H.sub.2 O, a solid abrasive material, and a third component selected from the group consisting of HNO.sub.3, H.sub.2 SO.sub.4, and AgNO.sub.3 or mixtures thereof; and b) chemical mechanical polishing a predominately copper containing metal layer on a semiconductor substrate with the slurry. Such slurry also constitutes part of the invention. Such slurry may also contain an additional oxidant selected from the group consisting of H.sub.2 O.sub.2, HOCl, KOCl, KMgO.sub.4 and CH.sub.3 COOH or mixtures thereof to form a copper oxide passivating-type layer at the copper surface.
    Type: Grant
    Filed: June 4, 1992
    Date of Patent: July 6, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Trung T. Doan
  • Patent number: 5222329
    Abstract: A method and system for controlling the depth of removal by polishing of a selected material on a supporting underlayer where it is desired to terminate removal of the selected material, such as tungsten, at the material-underlayer interface. In accordance with this novel method and system, the selected material such as a surface metallization layer is polished to initiate removal thereof in the direction of the material-underlayer interface. A microphone is positioned at a predetermined distance from the wafer to sense acoustical waves generated when the depth of material removal reaches a certain determinable distance from the interface to thereby generate output detection signals. These output detection signals are amplified and then applied to a spectrum analyzer which operates to analyze the sound intensity-versus-frequency characteristic of the acoustical waves received by the microphone.
    Type: Grant
    Filed: March 26, 1992
    Date of Patent: June 29, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Chris C. Yu
  • Patent number: 5209816
    Abstract: A semiconductor processing method of chemical mechanical polishing an aluminum containing metal layer on a semiconductor substrate includes, a) providing a chemical mechanical polishing slurry comprising H.sub.3 PO.sub.4 at from about 0.1% to about 20% by volume; H.sub.2 O.sub.2 at from about 1% to about 30% by volume, H.sub.2 O, and a solid abrasive material; and b) chemical mechanical polishing an aluminum containing metal layer on a semiconductor substrate with the slurry. Such process and slurry are also usable in chemical mechanical polishing of other layers, such as Ti, TiN and TiW materials. Such enables chemical mechanical polishing of a barrier metal/aluminum layer composite in a single polishing step, leading to increased controllability and resulting increased throughput. With respect to aluminum containing metal layers, the H.sub.2 O.sub.2 is understood to cause oxidation to aluminum oxide, which is subsequently removed by both chemical and mechanical action the result of the polish and slurry.
    Type: Grant
    Filed: June 4, 1992
    Date of Patent: May 11, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Trung T. Doan, Alan E. Laulusa
  • Patent number: 5188723
    Abstract: A process for selectively electrodepositing a pattern of metal such as copper on a substrate comprises the deposition of two successive layers over the entire substrate, photolithographic patterning of the upper layer, and placement of the exposed part of the first deposited layer to a lower surface potential then the patterned second layer. The metal is then deposited under a periodical modulated voltage signal that is adjusted in reference to the reduction potential of the metal so that any metal deposited on the exposed part of the first layer during the positive duty cycle of the signal is removed during the negative duty cycle while little or none of the metal deposited on the second layer is removed due to the second layer higher surface potential. The remaining exposed part of the first layer is etched away after the electrodeposition process is terminated.
    Type: Grant
    Filed: April 13, 1992
    Date of Patent: February 23, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Chris C. Yu, Gurtej S. Sandhu, Terry Gilton