Patents by Inventor Luan C. Tran

Luan C. Tran 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: 7790531
    Abstract: Different portions of a continuous loop of semiconductor material are electrically isolated from one another. In some embodiments, the end of the loop is electrically isolated from mid-portions of the loop. In some embodiments, loops of semiconductor material, having two legs connected together at their ends, are formed by a pitch multiplication process in which loops of spacers are formed on sidewalls of mandrels. The mandrels are removed and a block of masking material is overlaid on at least one end of the spacer loops. In some embodiments, the blocks of masking material overlay each end of the spacer loops. The pattern defined by the spacers and the blocks are transferred to a layer of semiconductor material. The blocks electrically connect together all the loops. A select gate is formed along each leg of the loops. The blocks serve as sources/drains.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: September 7, 2010
    Assignee: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Patent number: 7776683
    Abstract: A method for defining patterns in an integrated circuit comprises defining a plurality of features in a first photoresist layer using photolithography over a first region of a substrate. The method further comprises using pitch multiplication to produce at least two features in a lower masking layer for each feature in the photoresist layer. The features in the lower masking layer include looped ends. The method further comprises covering with a second photoresist layer a second region of the substrate including the looped ends in the lower masking layer. The method further comprises etching a pattern of trenches in the substrate through the features in the lower masking layer without etching in the second region. The trenches have a trench width.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: August 17, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Luan C. Tran, John Lee, Zengtao “Tony” Liu, Eric Freeman, Russell Nielsen
  • Patent number: 7759197
    Abstract: Crisscrossing spacers formed by pitch multiplication are used as a mask to form isolated features, such as contacts vias. A first plurality of mandrels are formed on a first level and a first plurality of spacers are formed around each of the mandrels. A second plurality of mandrels is formed on a second level above the first level. The second plurality of mandrels is formed so that they cross, e.g., are orthogonal to, the first plurality of mandrels, when viewed in a top down view. A second plurality of spacers is formed around each of the second plurality of mandrels. The first and the second mandrels are selectively removed to leave a pattern of voids defined by the crisscrossing first and second pluralities of spacers. These spacers can be used as a mask to transfer the pattern of voids to a substrate. The voids can be filled with material, e.g., conductive material, to form conductive contacts.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: July 20, 2010
    Assignee: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Patent number: 7749848
    Abstract: Non-volatile memory devices and arrays are described that facilitate the use of band-gap engineered gate stacks with asymmetric tunnel barriers in floating gate memory cells in NOR or NAND memory architectures that allow for direct tunneling programming and erase with electrons and holes, while maintaining high charge blocking barriers and deep carrier trapping sites for good charge retention. The direct tunneling program and erase capability reduces damage to the gate stack and the crystal lattice from high energy carriers, reducing write fatigue and leakage issues and enhancing device lifespan. Memory cells of the present invention also allow multiple bit storage in a single memory cell, and allow for programming and erase with reduced voltages. A positive voltage erase process via hole tunneling is also provided.
    Type: Grant
    Filed: September 12, 2007
    Date of Patent: July 6, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Arup Bhattacharyya, Kirk D. Prall, Luan C. Tran
  • Patent number: 7659161
    Abstract: The invention includes memory arrays, and methods which can be utilized for forming memory arrays. A patterned etch stop can be used during memory array fabrication, with the etch stop covering storage node contact locations while leaving openings to bitline contact locations. An insulative material can be formed over the etch stop and over the bitline contact locations, and trenches can be formed through the insulative material. Conductive material can be provided within the trenches to form bitline interconnect lines which are in electrical contact with the bitline contact locations, and which are electrically isolated from the storage node contact locations by the etch stop. In subsequent processing, openings can be formed through the etch stop to the storage node contact locations. Memory storage devices can then be formed within the openings and in electrical contact with the storage node contact locations.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: February 9, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Luan C. Tran, Fred D. Fishburn
  • Patent number: 7648919
    Abstract: A method for defining patterns in an integrated circuit comprises defining a plurality of features in a first photoresist layer using photolithography over a first region of a substrate. The method further comprises using pitch multiplication to produce at least two features in a lower masking layer for each feature in the photoresist layer. The features in the lower masking layer include looped ends. The method further comprises covering with a second photoresist layer a second region of the substrate including the looped ends in the lower masking layer. The method further comprises etching a pattern of trenches in the substrate through the features in the lower masking layer without etching in the second region. The trenches have a trench width.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: January 19, 2010
    Inventors: Luan C. Tran, John Lee, Zengtao “Tony” Liu, Eric Freeman, Russell Nielsen
  • Patent number: 7611944
    Abstract: A method for defining patterns in an integrated circuit comprises defining a plurality of features in a first photoresist layer using photolithography over a first region of a substrate. The method further comprises using pitch multiplication to produce at least two features in a lower masking layer for each feature in the photoresist layer. The features in the lower masking layer include looped ends. The method further comprises covering with a second photoresist layer a second region of the substrate including the looped ends in the lower masking layer. The method further comprises etching a pattern of trenches in the substrate through the features in the lower masking layer without etching in the second region. The trenches have a trench width.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: November 3, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Luan C. Tran, John Lee, Zengtao “Tony” Liu, Eric Freeman, Russell Nielsen
  • Publication number: 20090152645
    Abstract: Different portions of a continuous loop of semiconductor material are electrically isolated from one another. In some embodiments, the end of the loop is electrically isolated from mid-portions of the loop. In some embodiments, loops of semiconductor material, having two legs connected together at their ends, are formed by a pitch multiplication process in which loops of spacers are formed on sidewalls of mandrels. The mandrels are removed and a block of masking material is overlaid on at least one end of the spacer loops. In some embodiments, the blocks of masking material overlay each end of the spacer loops. The pattern defined by the spacers and the blocks are transferred to a layer of semiconductor material. The blocks electrically connect together all the loops. A select gate is formed along each leg of the loops. The blocks serve as sources/drains.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 18, 2009
    Applicant: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Patent number: 7547604
    Abstract: Self-aligned recessed gate structures and method of formation are disclosed. Field oxide areas for isolation are first formed in a semiconductor substrate. A plurality of columns are defined in an insulating layer formed over the semiconductor substrate subsequent to which a thin sacrificial oxide layer is formed over exposed regions of the semiconductor substrate but not over the field oxide areas. A dielectric material is then provided on sidewalls of each column and over portions of the sacrificial oxide layer and of the field oxide areas. A first etch is conducted to form a first set of trenches within the semiconductor substrate and a plurality of recesses within the field oxide areas. A second etch is conducted to remove dielectric residue remaining on the sidewalls of the columns and to form a second set of trenches. Polysilicon is then deposited within the second set of trenches and within the recesses to form recessed conductive gates.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: June 16, 2009
    Assignee: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Patent number: 7538036
    Abstract: A patterned mask can be formed as follows. A first patterned photoresist is formed over a masking layer and utilized during a first etch into the masking layer. The first etch extends to a depth in the masking layer that is less than entirely through the masking layer. A second patterned photoresist is subsequently formed over the masking layer and utilized during a second etch into the masking layer. The combined first and second etches form openings extending entirely through the masking layer and thus form the masking layer into the patterned mask. The patterned mask can be utilized to form a pattern in a substrate underlying the mask. The pattern formed in the substrate can correspond to an array of capacitor container openings. Capacitor structure can be formed within the openings. The capacitor structures can be incorporated within a DRAM array.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: May 26, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Brett W. Busch, Luan C. Tran, Ardavan Niroomand, Fred D. Fishburn, Yoshiki Hishiro, Ulrich C. Boettiger, Richard D. Holscher
  • Patent number: 7518184
    Abstract: Self-aligned recessed gate structures and method of formation are disclosed. Field oxide areas for isolation are first formed in a semiconductor substrate. A plurality of columns are defined in an insulating layer formed over the semiconductor substrate subsequent to which a thin sacrificial oxide layer is formed over exposed regions of the semiconductor substrate but not over the field oxide areas. A dielectric material is then provided on sidewalls of each column and over portions of the sacrificial oxide layer and of the field oxide areas. A first etch is conducted to form a first set of trenches within the semiconductor substrate and a plurality of recesses within the field oxide areas. A second etch is conducted to remove dielectric residue remaining on the sidewalls of the columns and to form a second set of trenches. Polysilicon is then deposited within the second set of trenches and within the recesses to form recessed conductive gates.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: April 14, 2009
    Assignee: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Publication number: 20090032963
    Abstract: Methods of fabricating semiconductor structures incorporating tight pitch contacts aligned with active area features and of simultaneously fabricating self-aligned tight pitch contacts and conductive lines using various techniques for defining patterns having sublithographic dimensions. Semiconductor structures having tight pitch contacts aligned with active area features and, optionally, aligned conductive lines are also disclosed, as are semiconductor structures with tight pitch contact holes and aligned trenches for conductive lines.
    Type: Application
    Filed: August 3, 2007
    Publication date: February 5, 2009
    Applicant: MICRON TECHNOLOGY, INC.
    Inventor: Luan C. Tran
  • Publication number: 20090035665
    Abstract: Spacers are formed by pitch multiplication and a layer of negative photoresist is deposited on and over the spacers to form additional mask features. The deposited negative photoresist layer is patterned, thereby removing photoresist from between the spacers in some areas. During patterning, it is not necessary to direct light to the areas where negative photoresist removal is desired, and the clean removal of the negative photoresist from between the spacers is facilitated. The pattern defined by the spacers and the patterned negative photoresist is transferred to one or more underlying masking layers before being transferred to a substrate.
    Type: Application
    Filed: July 31, 2007
    Publication date: February 5, 2009
    Applicant: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Publication number: 20090035584
    Abstract: Embodiments of a method for device fabrication by reverse pitch reduction flow include forming a first pattern of features above a substrate and forming a second pattern of pitch-multiplied spacers subsequent to forming the first pattern of features. In embodiments of the invention the first pattern of features may be formed by photolithography and the second pattern of pitch-multiplied spacers may be formed by pitch multiplication. Other methods for device fabrication are provided.
    Type: Application
    Filed: July 30, 2007
    Publication date: February 5, 2009
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Luan C. Tran, Raghupathy Giridhar
  • Patent number: 7449390
    Abstract: Methods of forming memory are described. According to one arrangement, a method of forming memory includes forming a plurality of word lines over a substrate, the word lines having insulating material thereover, forming a plurality of bit lines over the word lines, the bit lines having insulating material thereover, forming insulative material over the word lines and the bit lines, the insulative material being etchably different from the insulating material over the word lines and the insulating material over the bit lines, and selectively etching contact openings through the insulative material relative to the insulating material over the bit lines and the insulating material over the word lines, the openings being self-aligned to both the bit lines and word lines and extending to proximate the substrate.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: November 11, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Luan C. Tran
  • Publication number: 20080258245
    Abstract: One aspect of the invention encompasses a method of forming a semiconductor structure. A patterned line is formed to comprise a first layer and a second layer. The first layer comprises silicon and the second layer comprises a metal. The line has at least one sidewall edge comprising a first-layer-defined portion and a second-layer-defined portion. A third layer is formed along the at least one sidewall edge. The third layer comprises silicon and is along both the first layered defined portion of the sidewall edge and the second-layered-defined portion of the sidewall edge. The silicon of the third layer is reacted with the metal of the second layer to form a silicide along the second layer defined portion of the sidewall edge. The silicon of the third layer is removed to leave the silicon of the first layer, the metal of the second layer, and the silicide.
    Type: Application
    Filed: June 26, 2008
    Publication date: October 23, 2008
    Inventors: Leonard Forbes, Kie Y. Ahn, Luan C. Tran
  • Publication number: 20080227293
    Abstract: A method for defining patterns in an integrated circuit comprises defining a plurality of features in a first photoresist layer using photolithography over a first region of a substrate. The method further comprises using pitch multiplication to produce at least two features in a lower masking layer for each feature in the photoresist layer. The features in the lower masking layer include looped ends. The method further comprises covering with a second photoresist layer a second region of the substrate including the looped ends in the lower masking layer. The method further comprises etching a pattern of trenches in the substrate through the features in the lower masking layer without etching in the second region. The trenches have a trench width.
    Type: Application
    Filed: May 13, 2008
    Publication date: September 18, 2008
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Luan C. Tran, John Lee, Zengtao "Tony" Liu, Eric Freeman, Russell Nielsen
  • Patent number: 7405455
    Abstract: One aspect of the invention encompasses a method of forming a semiconductor structure. A patterned line is formed to comprise a first layer and a second layer. The first layer comprises silicon and the second layer comprises a metal. The line has at least one sidewall edge comprising a first-layer-defined portion and a second-layer-defined portion. A third layer is formed along the at least one sidewall edge. The third layer comprises silicon and is along both the first-layered-defined portion of the sidewall edge and the second-layered-defined portion of the sidewall edge. The silicon of the third layer is reacted with the metal of the second layer to form a silicide along the second-layer-defined portion of the sidewall edge. The silicon of the third layer is removed to leave the silicon of the first layer, the metal of the second layer, and the silicide.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: July 29, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn, Luan C. Tran
  • Publication number: 20080162781
    Abstract: Embodiments of the present invention provide apparatus, methods and systems that include a substrate including a central region and a peripheral region; a plurality of layers above a surface of the substrate, a first plurality of pitch-multiplied spacers on a top surface of the plurality of layer, the first plurality of pitch-multiplied spacers being above the central region of the substrate, and a second plurality of pitch-multiplied spacers on the top surface of the plurality of layers, the second plurality of pitch-multiplied spacers above the peripheral region and including at least one pitch-multiplied spacer having a surface at a distance from the at least one pitch multiplied spacer having a surface at the boundary.
    Type: Application
    Filed: December 29, 2006
    Publication date: July 3, 2008
    Inventors: Gordon Haller, Luan C. Tran
  • Patent number: 7384847
    Abstract: The invention includes memory arrays, and methods which can be utilized for forming memory arrays. A patterned etch stop can be used during memory array fabrication, with the etch stop covering storage node contact locations while leaving openings to bitline contact locations. An insulative material can be formed over the etch stop and over the bitline contact locations, and trenches can be formed through the insulative material. Conductive material can be provided within the trenches to form bitline interconnect lines which are in electrical contact with the bitline contact locations, and which are electrically isolated from the storage node contact locations by the etch stop. In subsequent processing, openings can be formed through the etch stop to the storage node contact locations. Memory storage devices can then be formed within the openings and in electrical contact with the storage node contact locations.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: June 10, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Luan C. Tran, Fred D. Fishburn