Etchant Contains Fluoride Ion Patents (Class 216/109)
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Patent number: 5895563Abstract: An iron immersion composition of matter is disclosed comprising a compound having a divalent or trivalent iron ion, a compound having a fluoride ion, and a compound having an acid hydrogen ion. A process for treating an aluminum substrate to improve the adhesion of metal layers to the substrate is also disclosed comprising contacting the substrate with the acidic iron immersion composition to produce an iron immersion coating on the alloy, and contacting the iron immersion coating with an etchant to substantially remove the coating and produce a microporous surface on the substrate.Type: GrantFiled: December 23, 1996Date of Patent: April 20, 1999Assignee: Atotech USA, Inc.Inventor: Yoshihisa Muranushi
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Patent number: 5868947Abstract: A processed Si product suitable for use as, for example, an X-ray mask, is produced by a process having the steps of preparing a non-porous Si substrate, changing by anodization at least a portion of the substrate into porous Si thereby forming at least one porous Si region penetrating the substrate from one to the other side thereof, and effecting an etching on the substrate by using an etchant containing hydrofluoric acid so as to remove the porous Si region. The substrate may be provided with an etching stop layer. In such a case, an unsupported membrane region formed by the etching stop layer is left after the removal of the porous Si region.Type: GrantFiled: January 3, 1996Date of Patent: February 9, 1999Assignee: Canon Kabushiki KaishaInventors: Kiyofumi Sakaguchi, Takao Yonehara
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Patent number: 5865900Abstract: A method for removing a metal-fluoropolymer residue from an integrated circuit structure within an integrated circuit. There is first provided an integrated circuit having formed therein a metal-fluoropolymer residue. The metal-fluoropolymer residue is formed from a first plasma etch method employing a fluorocarbon containing etchant gas composition within the presence of a conductor metal layer within the integrated circuit. The metal-fluoropolymer residue is then exposed to a second plasma etch method employing a chlorine containing etchant gas composition to form from the metal-fluoropolymer residue a chlorine containing plasma treated metal-fluoropolymer residue. Finally, the chlorine containing plasma treated metal-fluoropolymer residue is removed from the integrated circuit through a stripping method sequentially employing an aqueous acid solution followed by an organic solvent.Type: GrantFiled: October 4, 1996Date of Patent: February 2, 1999Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Chiarn-Lung Lee, Huai-Jen Shu, Ying-Tzu Yen
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Patent number: 5853492Abstract: A wet chemical process is provided for treating an emitter formed on a substrate of a field emission display, the process comprises applying a solution including hydrogen to the emitter. In one embodiment of the invention, the steps of applying a solution comprises applying a solution of hydrofluoric acid to the emitter.Type: GrantFiled: February 28, 1996Date of Patent: December 29, 1998Assignee: Micron Display Technology, Inc.Inventors: David A. Cathey, Terry Gilton
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Patent number: 5840205Abstract: A method of fabricating a specimen for analyzing defects of a semiconductor device is disclosed. The method includes the steps of: cutting a wafer to be adjacent to a defective portion that exists in a patterned layer formed on a substrate; molding the first specimen with a resin; grinding the substrate of the first specimen with a predetermined slope; and etching the ground face to expose the defective layer, wherein the wafer includes a semiconductor substrate and patterned layers where memory devices are formed on the semiconductor substrate.Type: GrantFiled: July 19, 1996Date of Patent: November 24, 1998Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Jeong-Hoi Koo, Doo-Jin Park
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Patent number: 5824601Abstract: A sacrificial oxide etching solution of carboxylic acid and HF having a high etch selectivity for silicon oxide relative to polysilicon, metal, and nitride. The solution is useful in the fabrication of microstructures having integrated electronics on the same chip. A carboxylic acid anhydride can be added to this solution to substantially remove all free water so that the etch selectivity to metal is improved. One specific solution is formed by mixing acetic acid, acetic anhydride, and aqueous HF.Type: GrantFiled: June 30, 1997Date of Patent: October 20, 1998Assignee: Motorola, Inc.Inventors: Patrick P. H. Dao, Paul William Dryer, Ping-Chang Lue, Michael J. Davison, Terry Andrew Willett, Margaret Leslie Kniffin, Rita Prasad Subrahmanyan
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Patent number: 5716535Abstract: A surface having exposed doped silicon dioxide such as BPSG is cleaned with a solution that etches thermal oxide at least one-third as fast as it etches the exposed doped silicon dioxide, resulting in more thorough cleaning with less removal of the exposed doped silicon dioxide. Specific applications to formation of container capacitors are disclosed. Preferred cleaning solutions include about 46 parts ammonium fluoride, about 9.5 parts hydrogen fluoride, and about 8.5 parts ammonium hydroxide in about 100 parts water by weight; and about 670 parts ammonium fluoride and about 3 parts hydrogen fluoride in about 1000 parts water by weight. The latter solution is also useful in cleaning methods in which a refractory metal silicide is exposed to the cleaning solution such as in cleaning prior to spacer formation or prior to a gate stack contact fill, in which case about 670 parts ammonium fluoride and about 1.6 parts hydrogen fluoride in about 1000 parts water is most preferred.Type: GrantFiled: March 5, 1996Date of Patent: February 10, 1998Assignee: Micron Technology, Inc.Inventors: Whonchee Lee, Richard C. Hawthorne, Li Li, Pai Hung Pan
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Patent number: 5716532Abstract: A method of improving the breakdown strength of polymer multi-layer (PML) capacitors is provided. The method comprises removing metal, specifically, aluminum, from the cut edge. This is done by either etching back the metal electrode layers in either basic or acidic solution or by anodizing the metal to cover that portion of the metal at the edge with an oxide. Removing the metal from the cut edge increases the breakdown strength of the PML capacitors by a factor of two or more.Type: GrantFiled: June 11, 1996Date of Patent: February 10, 1998Assignee: Sigma Labs, Inc.Inventors: Angelo Yializis, John G. Keimel, Alvin S. Rhorer, Trey W. Huntoon
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Patent number: 5707538Abstract: A magnetoresitive transducer has an insulating gap layer of variable thickness. The transducer includes a magnetoresistive layer disposed in an active region, and a first magnetic shield layer disposed in the active region and a field region. An insulating layer is spaced between the magnetoresistive layer and the magnetic shield layer. The insulating layer is thinner in the active region than in the field region. The probability of other layers bridging through the insulating layer in the field region is substantially reduced. The method of forming the transducer includes depositing a first insulating layer above the magnetic layer, and then selectively etching the first insulating layer by forming an opening in the active region having a cross-sectional profile sloping inwardly toward the magnetic shield layer. Thereafter, an insulating layer is deposited atop the first insulating layer having the opening.Type: GrantFiled: July 28, 1995Date of Patent: January 13, 1998Assignee: Read-Rite CorporationInventors: Yong Shen, T. C. Chuang
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Patent number: 5700383Abstract: Slurries and methods for the chemical mechanical polishing of thin films used in integrated circuit manufacturing are described. A first slurry comprises an oxidant, such as water, a halogen, such as fluorine, an abrasive, such as silica, and a chelating agent, such as citric acid, and has a pH between four and nine. The first slurry is ideal for the chemical mechanical polish of an aluminum film. Another slurry comprises an abrasive, such as silica, and an acid, such as citric acid, and has a pH of approximately three. The second slurry is ideal for the chemical mechanical polish of titanium aluminide and is compatible with the first slurry.Type: GrantFiled: December 21, 1995Date of Patent: December 23, 1997Assignee: Intel CorporationInventors: A. Daniel Feller, Kenneth C. Cadien
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Patent number: 5695661Abstract: The present invention is directed to a novel etching process for a semiconductor material which inhibits corrosion of metal comprised of pretreating the material, preferably with a surfactant, and then exposing the material to a mixture comprising salt, a buffered oxide etch, and optionally a surfactant.Type: GrantFiled: June 7, 1995Date of Patent: December 9, 1997Assignee: Micron Display Technology, Inc.Inventors: Robert T. Rasmussen, Surjit S. Chadha, David A. Cathey
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Patent number: 5645737Abstract: A surface having an exposed silicon/silica interface is cleaned by an HF dip, followed immediately by a rinse in citric acid, followed by a rinse in deionized water. Low pH of the citric acid significantly prevents the formation of a charge differential between the silica and silicon portions of the surface, which charge differential would otherwise cause any silica particles present to remain on the silicon portion of the surface. Surfactant properties of the citric acid help remove any silica particles from the surface. The deionized water rinse then removes the citric acid from the surfaces, leaving a very clean, low particulate surface on both the silica and silicon portions thereof, with little or no etching of the silicon portion.Type: GrantFiled: February 21, 1996Date of Patent: July 8, 1997Assignee: Micron Technology, Inc.Inventors: Karl M. Robinson, Michael A. Walker
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Patent number: 5646095Abstract: A method for selectively etching insulative material composed of SrTiO3 or MgO in the presence of a copper oxide perovskite superconductive material includes treating the insulative material with a liquid selective etchant solution containing hydrogen fluoride in water for a period of time, the insulative material being etched at a substantially faster rate than the superconductive material etch rate, then treating the superconductive material exposed to the insulative selective with another etchant to remove a surface layer.Type: GrantFiled: October 5, 1994Date of Patent: July 8, 1997Assignee: International Business Machines CorporationInventors: Walter Eidelloth, William Joseph Gallagher
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Patent number: 5635035Abstract: Etching the surfaces of a metal tower packing improves their wettability and therefore their efficiency in mass transfer applications.Type: GrantFiled: September 12, 1995Date of Patent: June 3, 1997Assignee: Norton Chemical Process Products CorporationInventor: T. Daniel Koshy
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Patent number: 5603849Abstract: Methods and compositions are disclosed for cleaning oxides and metals from surfaces of silicon wafers in a two-phase liquid system. The two-phase system comprises a fluorine containing oxide etchant, such as hydrofluoric acid, that is soluble within two immiscible liquids of different densities such that the two liquids form separate layers. Silicon wafers are immersed into the top layer which is a nonpolar organic liquid. The bottom layer is polar liquid, preferably water. The nonpolar organic liquid includes ketones, ethers, alkanes and alkenes, but is preferably pentanone. Metal ions are transported from surfaces of the silicon wafers through the pentanone top layer to the polar water bottom layer, thereby eliminating metal ions from the pentanone. Due to relative solubilities, the concentration of hydrofluoric acid in the water bottom layer is greater than in the pentanone top layer.Type: GrantFiled: November 15, 1995Date of Patent: February 18, 1997Assignee: Micron Technology, Inc.Inventor: Li Li
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Patent number: 5554254Abstract: A process for preventing the formation of precipitates on a substrate surface after a contact layer (e.g., tungsten layer) etch back. The process involves removing the precursor chemicals of the precipitate. In one embodiment of the invention, the precursors are removed after etching contact layer by rinsing the substrate in water at about 30.degree. C. for about 10 minutes. In a second embodiment of the invention, the precursors are removed by baking the substrate at a temperature of approximately 120.degree. C. for approximately 180 seconds.Type: GrantFiled: March 16, 1995Date of Patent: September 10, 1996Assignee: Taiwan Semiconductor Manufacturing CompanyInventors: Yuan-Chang Huang, Kuang-Hui Chang
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Patent number: 5540345Abstract: A process of producing a diffraction grating includes the steps of forming a coating layer on a first diffraction grating layer of a resin formed on a substrate without damaging the diffraction grating layer, removing a portion of the coating layer positioned on the first diffraction grating layer by etching to form a second diffraction grating layer of the coating layer having the reverse phase to that of the first diffraction grating layer, removing the first diffraction grating layer, and etching the substrate with a mask of the second diffraction grating layer, so that the diffraction grating having the reverse phase can be easily produced. When the first diffraction grating layer is left and both the first and second diffraction grating layers are used as a mask, the diffraction grating having a period half times as large as that of the first grating layer can be easily produced.Type: GrantFiled: December 27, 1993Date of Patent: July 30, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Sugimoto, Teruhito Matsui, Ken-ichi Ohtsuka, Yuji Abe, Toshiyuki Ohishi
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Patent number: 5516346Abstract: Novel slurries for the chemical mechanical polishing of thin films used in integrated circuit manufacturing. A tungsten slurry of the present invention comprises an oxidizing agent, such as potassium ferricyanide, an abrasive such as silica, and has a pH between two and four. The tungsten slurry of the present invention can be used in a chemical mechanical planarization process to polish back a blanket deposited tungsten film to form plugs or vias. The tungsten slurry can also be used to polish copper, tungsten silicide, and titanium nitride. A second slurry, which is a 9:1 dilution of the tungsten slurry is ideal for chemical mechanical polishing of titanium nitride films. A third slurry of the present invention comprises a fluoride salt, an abrasive such as silica and has a pH.ltoreq.8. The third slurry can be used to polish titanium films.Type: GrantFiled: May 13, 1994Date of Patent: May 14, 1996Assignee: Intel CorporationInventors: Kenneth C. Cadien, Daniel A. Feller
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Patent number: 5492235Abstract: A method for removing Ball Limiting Metallurgy (BLM) layers from the surface of a wafer in the presence of Pb/Sn solder bumps. In one embodiment, the BLM comprises two layers: titanium and copper. After Pb/Sn solder bumps have been formed over the electrical contact pads of the wafer, the BLM copper layer is etched with a H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O solution. While removing the copper layer, the H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O etchant also reacts with the Pb/Sn solder bumps to form a thin PbO protective layer over the surface of the bumps. When the copper layer has been etched away, the titanium layer is etched with a CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O solution. The PbO layer formed over the surface of the Pb/Sn solder bumps remain insoluble when exposed to the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant, thereby preventing the solder bumps from being etched in the presence of the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant.Type: GrantFiled: December 1, 1994Date of Patent: February 20, 1996Assignee: Intel CorporationInventors: Douglas E. Crafts, Venkatesan Murali, Caroline S. Lee
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Patent number: 5477976Abstract: A brightening chemical polishing solution for a hardened steel article (e.g., a carburized and quenched gear) comprises hydrofluoric acid having a molar concentration of from 0.2 to 2 mol/l, hydrogen peroxide having a molar concentration of from 0.4 to 4 mol/l, and water, a molar ratio of the hydrofluoric acid to the hydrogen peroxide being from 1:1.5 to 1:2.8. The steel article is quench hardened and is chemically polished in the solution. A shot-peening is additionally performed, prior to the polishing.Type: GrantFiled: April 29, 1993Date of Patent: December 26, 1995Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Toyota Jidosha Kabushiki KaishaInventors: Kenichi Suzuki, Masaki Kajino, Kazuyoshi Ogawa, Takashi Asano, Mineo Ogino, Hideo Aihara, Fumio Shimizu, Masazumi Onishi, Yasuyuki Suzuki