Patents by Inventor Christophe Pierrat

Christophe Pierrat 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).

  • Publication number: 20010024883
    Abstract: A process for producing multiple undercut profiles in a single material. A resist pattern is applied over a work piece and a wet etch is performed to produce an undercut in the material. This first wet etch is followed by a polymerizing dry etch which produces a polymer film in the undercut created by the first wet etch. The polymer film prevents further etching of the undercut portion during a second wet etch. Thus, an undercut profile can be obtained having a larger undercut in an underlying portion of the work piece, utilizing only a single resist application step. The work piece may be a multi-layer work piece having different layers formed of the same material, or it may be a single layer of material.
    Type: Application
    Filed: March 23, 2001
    Publication date: September 27, 2001
    Applicant: Micron Technology, Inc.
    Inventors: Karen Huang, Christophe Pierrat
  • Publication number: 20010023045
    Abstract: Methods of reducing proximity effects in lithographic processes wherein an integrated circuitry pattern is transferred from a mask onto a semiconductor substrate are described. In one embodiment, a desired spacing is defined between a main feature which is to reside on a mask and which is to be transferred onto the substrate, and an adjacent proximity effects-correcting feature. After the spacing definition, the dimensions of the main feature, are adjusted relative to the proximity effects-correcting feature to achieve a desired transferred main feature dimension. In another embodiment, a desired spacing is defined between a main feature having an edge and an adjacent sub-resolution feature. The edge of the main feature is moved relative to the sub-resolution feature to achieve a desired transferred main feature dimension.
    Type: Application
    Filed: February 12, 2001
    Publication date: September 20, 2001
    Inventors: Christophe Pierrat, James E. Burdorf, William Baggenstoss, William Stanton
  • Patent number: 6284419
    Abstract: Methods of reducing proximity effects in lithographic processes wherein an integrated circuitry pattern is transferred from a mask onto a semiconductor substrate are described. In one embodiment, a desired spacing is defined between a main feature which is to reside on a mask and which is to be transferred onto the substrate, and an adjacent proximity effects-correcting feature. After the spacing definition, the dimensions of the main feature are adjusted relative to the proximity effects-correcting feature to achieve a desired transferred main feature dimension. In another embodiment, a desired spacing is defined between a main feature having an edge and an adjacent sub-resolution feature. The edge of the main feature is moved relative to the sub-resolution feature to achieve a desired transferred main feature dimension.
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: September 4, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Christophe Pierrat, James E. Burdorf, William Baggenstoss, William Stanton
  • Publication number: 20010015796
    Abstract: Photolithographic methods and apparatus for reducing or eliminating the proximity effect. Multiple exposures using different exposure parameters are used to reduce or to eliminate the proximity effect.
    Type: Application
    Filed: February 20, 2001
    Publication date: August 23, 2001
    Inventor: Christophe Pierrat
  • Patent number: 6272236
    Abstract: An improved technique for inspecting photomasks employs simulated images of the resist pattern. A simulated image of an original pattern is compared to a simulated image generated from a pattern captured from a photomask manufactured from the original pattern. Alternatively, simulated images generated from captured data from two different instances of the same original pattern formed in a photomask are compared.
    Type: Grant
    Filed: July 18, 2000
    Date of Patent: August 7, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Christophe Pierrat, James Burdorf
  • Publication number: 20010011199
    Abstract: The shape of chrome patterns on an optical pattern transfer tool are adjusted to get a desired shape on a wafer in the manufacture of semiconductor devices, wherein very small regions on a photoresist are defined and these regions are controlled with a high degree of accuracy. The optical pattern transfer tool has first and second planar surfaces lying in substantially parallel planes and a plurality of opaque regions overlying the first planar surface. First and second steps formed between and the first and second planar surfaces at first and second edges, respectively, define a width of the first planar surface. Each of the opaque regions are spaced from one another and offset from one another such that they are alternately aligned along a length of the first planar surface, such that one of the opaque regions is aligned with a portion of the first edge and the next one of the opaque regions along the length is aligned with a portion of the second edge.
    Type: Application
    Filed: January 23, 2001
    Publication date: August 2, 2001
    Applicant: Micron Technology, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 6268091
    Abstract: A subresolution grating composed of approximately circular contacts is fabricated around the border of the primary pattern of a photomask. As a result, resolution at the edges of the photomask pattern is improved when the pattern is printed on a wafer surface. In addition, the reduced leakage enables a more efficient use of the glass plate on which the photomask is fabricated as well as a more efficient use of the wafer surface as a result of being able to place patterns closer together.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: July 31, 2001
    Assignee: Micron
    Inventor: Christophe Pierrat
  • Patent number: 6255024
    Abstract: An improved photolithographic method employs a pattern of subresolution openings to enhance the printability of clear-field patterns. Incorporating a subresolution opening along the edges of the transmission areas prevents the printing of side lobe light and enables incorporation of a positive bias in the clear-field pattern. This is turn increases the lithographic process latitudes. The photomask must be significantly overexposed as a result of using a positive bias. To compensate for the impact of increased exposure on large transmission areas and avoid degradation of the corresponding resist, a pattern of subresolution openings is incorporated in the large transmission areas. The size and orientation of the subresolution areas creates a diffraction grating effect, reducing the exposure of the area under each transmission area.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: July 3, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Christophe Pierrat
  • Publication number: 20010002304
    Abstract: Methods of reducing proximity effects in lithographic processes wherein an integrated circuitry pattern is transferred from a mask onto a semiconductor substrate are described. In one embodiment, a desired spacing is defined between a main feature which is to reside on a mask and which is to be transferred onto the substrate, and an adjacent proximity effects-correcting feature. After the spacing definition, the dimensions of the main feature are adjusted relative to the proximity effects-correcting feature to achieve a desired transferred main feature dimension. In another embodiment, a desired spacing is defined between a main feature having an edge and an adjacent sub-resolution feature. The edge of the main feature is moved relative to the sub-resolution feature to achieve a desired transferred main feature dimension.
    Type: Application
    Filed: January 24, 2001
    Publication date: May 31, 2001
    Inventors: Christophe Pierrat, James E. Burdorf, William Baggenstoss, William Stanton
  • Patent number: 6238824
    Abstract: There are provided methods for making a reticle for use in a photolithography process, comprising generating an first reticle layout having at least one printable reticle feature, generating a modified reticle layout having the first reticle layout and at least one correction area, generating an alignment budget-containing reticle layout having at least one different printable reticle feature and at least one alignment budget border area, and removing from the modified reticle layout any area of overlap between the at least one correction area and the at least one alignment budget border area. There are also provided reticles formed according to such methods. In addition, there are provided computer-implemented methods for designing such a reticle, as well as computer readable storage media, and computer systems for use in making such reticles. In addition, there are provided photolithographic processes using such a reticle.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: May 29, 2001
    Assignee: Micron Technology, Inc.
    Inventors: John R. Futrell, Christophe Pierrat, William Stanton
  • Publication number: 20010001693
    Abstract: A phase shifting mask can be used with exposure lights of two different wavelengths. The depth of the phase shifting layer is calculated and fabricated such that it shifts a first exposure light about 180° and a second exposure light about 180°.
    Type: Application
    Filed: December 8, 2000
    Publication date: May 24, 2001
    Applicant: Micron Technology, Inc.
    Inventors: Christophe Pierrat, J. Brett Rolfson
  • Patent number: 6235638
    Abstract: A process for producing multiple undercut profiles in a single material. A resist pattern is applied over a work piece and a wet etch is performed to produce an undercut in the material. This first wet etch is followed by a polymerizing dry etch which produces a polymer film in the undercut created by the first wet etch. The polymer film prevents further etching of the undercut portion during a second wet etch. Thus, an undercut profile can be obtained having a larger undercut in an underlying portion of the work piece, utilizing only a single resist application step. The work piece may be a multi-layer work piece having different layers formed of the same material, or it may be a single layer of material.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: May 22, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Karen Huang, Christophe Pierrat
  • Patent number: 6232191
    Abstract: This invention teaches methods and apparatus for forming self-aligned photosensitive material spacers about protruding structures in semiconductor devices. One embodiment of the invention is a method for forming a LDD structure, utilizing disposable photosensitive material spacers. A second embodiment of the invention comprises a method for forming a transistor, having salicided source/drain regions, utilizing photosensitive polyimide spacers for forming the salicided source/drain regions, without disposing of the spacers. A third embodiment of the invention comprises a method for creating an offset from a protruding structure on a semiconductor substrate, using disposable photosensitive material spacers.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: May 15, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Nanseng Jeng, Christophe Pierrat
  • Patent number: 6225174
    Abstract: This invention teaches methods and apparatus for forming self-aligned photosensitive material spacers about protruding structures in semiconductor devices. One embodiment of the invention is a method for forming a lightly doped drain (LDD) structure, utilizing disposable photosensitive material spacers. A second embodiment of the invention comprises a method for forming a transistor, having salicided source/drain regions, utilizing photosensitive polyimide spacers for forming the salicided source/drain regions, without disposing of the spacers. A third embodiment of the invention comprises a method for creating an offset from a protruding structure on a semiconductor substrate, using disposable photosensitive material spacers.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: May 1, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Nanseng Jeng, Christophe Pierrat
  • Patent number: 6221564
    Abstract: This invention teaches methods and apparatus for forming self-aligned photosensitive material spacers about protruding structures in semiconductor devices. One embodiment of the invention is a method for forming a lightly doped drain (LDD) structure, utilizing disposable photosensitive material spacers. A second embodiment of the invention comprises a method for forming a transistor, having salicided source/drain regions, utilizing photosensitive polyimide spacers for forming the salicided source/drain regions, without disposing of the spacers. A third embodiment of the invention comprises a method for creating an offset from a protruding structure on a semiconductor substrate, using disposable photosensitive material spacers.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: April 24, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Nanseng Jeng, Christophe Pierrat
  • Patent number: 6218089
    Abstract: Photolithographic methods and apparatus for reducing or eliminating the proximity effect. Multiple exposures using different exposure parameters are used to reduce or to eliminate the proximity effect.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: April 17, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 6200906
    Abstract: Stepped photoresist profiles provide various methods of forming profiles in an underlying substrate. The stepped photoresist profiles are formed in two layers of photoresist that are disposed over the substrate. The substrate is then etched twice using a respective opening in each photoresist layer to create a stepped profile in the substrate.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: March 13, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Shubneesh Batra, Christophe Pierrat
  • Patent number: 6185473
    Abstract: The shape of chrome patterns on an optical pattern transfer tool are adjusted to get a desired shape on a wafer in the manufacture of semiconductor devices, wherein very small regions on a photoresist are defined and these regions are controlled with a high degree of accuracy. The optical pattern transfer tool has first and second planar surfaces lying in substantially parallel planes and a plurality of opaque regions overlying the first planar surface. First and second steps formed between and the first and second planar surfaces at first and second edges, respectively, define a width of the first planar surface. Each of the opaque regions are spaced from one another and offset from one another such that they are alternately aligned along a length of the first planar surface, such that one of the opaque regions is aligned with a portion of the first edge and the next one of the opaque regions along the length is aligned with a portion of the second edge.
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: February 6, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 6178360
    Abstract: A system and method for enhancing process latitude (tolerances) in the fabrication of devices and integrated circuits. A measuring point is selected corresponding to a feature of critical dimension. Then the pattern is convolved with the model, and its value and rate of change are calculated over a range of corresponding values of a first process parameter. Next, an optimum threshold having the largest rate of change, or contrast, is selected. Finally, proximity correction is performed using relevant parameters.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: January 23, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Christophe Pierrat, James Burdorf
  • Patent number: 6162568
    Abstract: A phase shifting mask can be used to form features on a semiconductor wafer with exposure lights of two different wavelengths. The depth of the phase shifting layer is calculated and fabricated such that it shifts a first exposure light about 180.degree. and a second exposure light about 180.degree..
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: December 19, 2000
    Assignee: Micron Technology, Inc.
    Inventors: Christophe Pierrat, J. Brett Rolfson