Patents Assigned to LONGITUDE FLASH MEMORY SOLUTIONS LTD.
  • Patent number: 10784356
    Abstract: A method to integrate silicon-oxide-nitride-oxide-silicon (SONOS) transistors into a complementary metal-oxide-semiconductor (CMOS) flow including a triple gate oxide structure. The memory device may include a non-volatile memory (NVM) transistor that has a charge-trapping layer and a blocking dielectric, a first field-effect transistor (FET) including a first gate oxide of a first thickness, a second FET including a second gate oxide of a second thickness, a third FET including a third gate oxide of a third thickness, in which the first thickness is greater than the second thickness and the second thickness is greater than the third thickness.
    Type: Grant
    Filed: August 8, 2018
    Date of Patent: September 22, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Krishnaswamy Ramkumar, Igor Kouznetsov, Venkatraman Prabhakar, Ali Keshavarzi
  • Patent number: 10784277
    Abstract: A memory device that includes a non-volatile memory (NVM) transistor disposed in a first region of a substrate. The NVM transistor includes a first gate including a first type of conductor material. The memory device further includes a first type of low voltage field-effect transistor (LV FET) and an input/out field-effect transistor (I/O FET) disposed in a second region of the substrate. The LV FET includes a second gate comprising a second type of conductor material, the I/O FET includes a third gate comprising a second type of conductor material, and the first and second conductor materials are different. Other embodiments are also described.
    Type: Grant
    Filed: January 4, 2018
    Date of Patent: September 22, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventor: Krishnaswamy Ramkumar
  • Patent number: 10706937
    Abstract: A method of performing an operation on a non-volatile memory (NVM) cell of a memory device is disclosed. The pass transistor of the NVM cell is an asymmetric transistor including a source with a halo implant. The source of the pass transistor is coupled to a common source line (CSL) that is shared among NVM cells of a sector of NVM cells. The operation may be performed by applying a first signal to a word line (WLS) coupled to a gate of a memory transistor of the NVM cell and applying a second signal to a bit line (BL) coupled to a drain of the memory transistor of the NVM cell.
    Type: Grant
    Filed: September 16, 2019
    Date of Patent: July 7, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Sungkwon Lee, Venkatraman Prabhakar
  • Patent number: 10699901
    Abstract: A method of scaling a nonvolatile trapped-charge memory device and the device made thereby is provided. In an embodiment, the method includes forming a channel region including polysilicon electrically connecting a source region and a drain region in a substrate. A tunneling layer is formed on the substrate over the channel region by oxidizing the substrate to form an oxide film and nitridizing the oxide film. A multi-layer charge trapping layer including an oxygen-rich first layer and an oxygen-lean second layer is formed on the tunneling layer, and a blocking layer deposited on the multi-layer charge trapping layer. In one embodiment, the method further includes a dilute wet oxidation to densify a deposited blocking oxide and to oxidize a portion of the oxygen-lean second layer.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: June 30, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Frederick B. Jenne, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Patent number: 10700083
    Abstract: An embodiment of a method of integration of a non-volatile memory device into a logic MOS flow is described. Generally, the method includes: forming a pad dielectric layer of a MOS device above a first region of a substrate; forming a channel of the memory device from a thin film of semiconducting material overlying a surface above a second region of the substrate, the channel connecting a source and drain of the memory device; forming a patterned dielectric stack overlying the channel above the second region, the patterned dielectric stack comprising a tunnel layer, a charge-trapping layer, and a sacrificial top layer; simultaneously removing the sacrificial top layer from the second region of the substrate, and the pad dielectric layer from the first region of the substrate; and simultaneously forming a gate dielectric layer above the first region of the substrate and a blocking dielectric layer above the charge-trapping layer.
    Type: Grant
    Filed: August 11, 2015
    Date of Patent: June 30, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Krishnaswamy Ramkumar, Bo Jin, Fredrick B. Jenne
  • Patent number: 10615289
    Abstract: An embodiment of a nonvolatile charge trap memory device is described. In one embodiment, the device comprises a channel comprising silicon overlying a surface on a substrate electrically connecting a first diffusion region and a second diffusion region of the memory device, and a gate stack intersecting and overlying at least a portion of the channel, the gate stack comprising a tunnel oxide abutting the channel, a split charge-trapping region abutting the tunnel oxide, and a multi-layer blocking dielectric abutting the split charge-trapping region. The split charge-trapping region includes a first charge-trapping layer comprising a nitride closer to the tunnel oxide, and a second charge-trapping layer comprising a nitride overlying the first charge-trapping layer. The multi-layer blocking dielectric comprises at least a high-K dielectric layer.
    Type: Grant
    Filed: August 30, 2016
    Date of Patent: April 7, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Patent number: 10593812
    Abstract: A method for fabricating a nonvolatile charge trap memory device is described. The method includes subjecting a substrate to a first oxidation process to form a tunnel oxide layer overlying a polysilicon channel, and forming over the tunnel oxide layer a multi-layer charge storing layer comprising an oxygen-rich, first layer comprising a nitride, and an oxygen-lean, second layer comprising a nitride on the first layer. The substrate is then subjected to a second oxidation process to consume a portion of the second layer and form a high-temperature-oxide (HTO) layer overlying the multi-layer charge storing layer. The stoichiometric composition of the first layer results in it being substantially trap free, and the stoichiometric composition of the second layer results in it being trap dense. The second oxidation process can comprise a plasma oxidation process or a radical oxidation process using In-Situ Steam Generation.
    Type: Grant
    Filed: June 5, 2018
    Date of Patent: March 17, 2020
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Krishnaswamy Ramkumar, Sagy Charel Levy, Jeong Soo Byun
  • Patent number: 10510387
    Abstract: A method for driving a non-volatile memory system is disclosed. A standby detection circuit detects whether the nonvolatile memory system is in a standby condition. In response to determining that the non-volatile memory system is in a standby condition, a bias control circuit reduces bias currents provided to drivers of the non-volatile memory system in a standby mode. The non-volatile memory system is operated in the standby mode after the bias currents have been reduced, where an output signal indicating the standby mode is maintained until a read instruction is detected.
    Type: Grant
    Filed: August 6, 2018
    Date of Patent: December 17, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Cristinel Zonte, Vijay Raghavan, Iulian Gradinariu, Gary Peter Moscaluk, Roger Jay Bettman, Vineet Argrawal, Samuel Leshner
  • Patent number: 10446656
    Abstract: Semiconductor devices including non-volatile memory transistors and methods of fabricating the same to improve performance thereof are provided. In one embodiment, the memory transistor comprises an oxide-nitride-oxide (ONO) stack on a surface of a semiconductor substrate, and a high work function gate electrode formed over a surface of the ONO stack. Preferably, the gate electrode comprises a doped polysilicon layer, and the ONO stack comprises multi-layer charge storing layer including at least a substantially trap free bottom oxynitride layer and a charge trapping top oxynitride layer. More preferably, the device also includes a metal oxide semiconductor (MOS) logic transistor formed on the same substrate, the logic transistor including a gate oxide and a high work function gate electrode. In certain embodiments, the dopant is a P+ dopant and the memory transistor comprises N-type (NMOS) silicon-oxide-nitride-oxide-silicon (SONOS) transistor while the logic transistor a P-type (PMOS) transistor.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: October 15, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Patent number: 10424592
    Abstract: A method of fabricating a memory device is described. Generally, the method includes: forming on a surface of a substrate a dielectric stack including a tunneling dielectric and a charge-trapping layer overlying the tunneling dielectric; forming a cap layer overlying the dielectric stack, wherein the cap layer comprises a multi-layer cap layer including at least a first cap layer overlying the charge-trapping layer, and a second cap layer overlying the first cap layer; patterning the cap layer and the dielectric stack to form a gate stack of a memory device; removing the second cap layer; and performing an oxidation process to oxidize the first cap layer to form a blocking oxide overlying the charge-trapping layer, wherein the oxidation process consumes the first cap layer. Other embodiments are also described.
    Type: Grant
    Filed: July 24, 2018
    Date of Patent: September 24, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventor: Krishnaswamy Ramkumar
  • Patent number: 10418373
    Abstract: A method of controlling the thickness of gate oxides in an integrated CMOS process which includes performing a two-step gate oxidation process to concurrently oxidize and therefore consume at least a first portion of the cap layer of the NV gate stack to form a blocking oxide and form a gate oxide of at least one metal-oxide-semiconductor (MOS) transistor in the second region, wherein the gate oxide of the at least one MOS transistor is formed during both a first oxidation step and a second oxidation step of the gate oxidation process.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: September 17, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventor: Krishnaswamy Ramkumar
  • Patent number: 10418110
    Abstract: A method of performing an operation on a non-volatile memory (NVM) cell of a memory device is disclosed. The pass transistor of the NVM cell is an asymmetric transistor including a source with a halo implant. The source of the pass transistor is coupled to a common source line (CSL) that is shared among NVM cells of a sector of NVM cells. The operation may be performed by applying a first signal to a word line (WLS) coupled to a gate of a memory transistor of the NVM cell and applying a second signal to a bit line (BL) coupled to a drain of the memory transistor of the NVM cell.
    Type: Grant
    Filed: July 3, 2018
    Date of Patent: September 17, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Sungkwon Lee, Venkatraman Prabhakar
  • Patent number: 10411103
    Abstract: Semiconductor devices including non-volatile memory transistors and methods of fabricating the same to improve performance thereof are provided. In one embodiment, the memory transistor comprises an oxide-nitride-oxide (ONO) stack on a surface of a semiconductor substrate, and a high work function gate electrode formed over a surface of the ONO stack. Preferably, the gate electrode comprises a doped polysilicon layer, and the ONO stack comprises multi-layer charge storing layer including at least a substantially trap free bottom oxynitride layer and a charge trapping top oxynitride layer. More preferably, the device also includes a metal oxide semiconductor (MOS) logic transistor formed on the same substrate, the logic transistor including a gate oxide and a high work function gate electrode. In certain embodiments, the dopant is a P+ dopant and the memory transistor comprises N-type (NMOS) silicon-oxide-nitride-oxide-silicon (SONOS) transistor while the logic transistor a P-type (PMOS) transistor.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: September 10, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Patent number: 10373688
    Abstract: A method of erasing, during an erase operation, a non-volatile memory (NVM) cell of a memory device is disclosed. The erasing includes applying a first HV signal (VPOS) to a common source line (CSL). The CSL is shared among NVM cells of a sector of NVM cells. The first HV signal is above a highest voltage of a power supply. The erasing also includes applying the first HV signal to a local bit line (BL).
    Type: Grant
    Filed: June 27, 2017
    Date of Patent: August 6, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Bogdan I. Georgescu, Gary P. Moscaluk, Vijay Raghavan, Igor G. Kouznetsov
  • Patent number: 10374067
    Abstract: An embodiment of a semiconductor memory device including a multi-layer charge storing layer and methods of forming the same are described. Generally, the device includes a channel formed from a semiconducting material overlying a surface on a substrate connecting a source and a drain of the memory device; a tunnel oxide layer overlying the channel; and a multi-layer charge storing layer including an oxygen-rich, first oxynitride layer on the tunnel oxide layer in which a stoichiometric composition of the first oxynitride layer results in it being substantially trap free, and an oxygen-lean, second oxynitride layer on the first oxynitride layer in which a stoichiometric composition of the second oxynitride layer results in it being trap dense. In one embodiment, the device comprises a non-planar transistor including a gate having multiple surfaces abutting the channel, and the gate comprises the tunnel oxide layer and the multi-layer charge storing layer.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: August 6, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Sagy Levy, Krishnaswamy Ramkumar, Fredrick Jenne, Sam Geha
  • Patent number: 10332599
    Abstract: A memory device that includes a non-volatile memory (NVM) array, divided into a flash memory portion and an electrically erasable programmable read-only memory (EEPROM) portion. The NVM array includes charge-trapping memory cells arranged in rows and columns, in which each memory cell has a memory transistor including an angled lightly doped drain (LDD) implant, and a select transistor including a shared source region with a halo implant. The flash memory portion and the EEPROM portion are disposed within one single semiconductor die. Other embodiments are also disclosed.
    Type: Grant
    Filed: March 12, 2018
    Date of Patent: June 25, 2019
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Gary Menezes, Krishnaswamy Ramkumar, Ali Keshavarzi, Venkatraman Prabhakar