Patents by Inventor Krishnaswamy Ramkumar

Krishnaswamy Ramkumar 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: 20240107771
    Abstract: A fabrication method of a semiconductor device is described. Generally, the method includes forming a customizable oxide-nitride-oxide (ONO) stack over a substrate in an in-situ atomic layer deposition (ALD) tool or chamber. Radical oxidation or oxide deposition process steps are performed to form tunnel dielectric layer overlying the substrate. Silicon nitride deposition process steps are also performed to form a multi-layer charge trapping (CT) layer in which at least some of the process parameters of silicon nitride deposition process steps are adjusted when forming the first and second CT sub-layers of the multi-layer CT layer. Subsequently, radical oxidation or oxide deposition process steps are performed in the ALD tool to form a blocking dielectric layer overlying the multi-layer CT layer.
    Type: Application
    Filed: September 27, 2022
    Publication date: March 28, 2024
    Applicant: Infineon Technologies LLC
    Inventors: Michael ALLEN, Krishnaswamy RAMKUMAR
  • Patent number: 11810616
    Abstract: A method of fabricating a multi-level memory cell that includes the steps of forming a shallow trench isolation (STI) in a substrate, performing clean and preclean process such that top surfaces of the STI and substrate are substantially leveled, forming a tunnel dielectric using a radical oxidation process, forming upper and lower silicon oxynitride layers in which an amount of electric charge trapped represents N×analog values stored in the multi-level memory cell, N is a natural number greater than 2, forming a blocking dielectric and patterning to form a memory stack, and forming a lightly-doped drain extension (LDD) adjacent to the memory stack by angled implant such that the LDD extends at least partly under the memory stack.
    Type: Grant
    Filed: May 19, 2022
    Date of Patent: November 7, 2023
    Assignee: Infineon Technologies LLC
    Inventors: Krishnaswamy Ramkumar, Venkatraman Prabhakar, Vineet Agrawal, Long Hinh, Santanu Kumar Samanta, Ravindra Kapre
  • Patent number: 11784243
    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: December 2, 2021
    Date of Patent: October 10, 2023
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD
    Inventors: Sagy Charel Levy, Krishnaswamy Ramkumar, Fredrick Jenne, Sam G Geha
  • Patent number: 11721733
    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: July 2, 2021
    Date of Patent: August 8, 2023
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Publication number: 20230209830
    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: Application
    Filed: January 30, 2023
    Publication date: June 29, 2023
    Inventors: Krishnaswamy Ramkumar, Bo Jin, Fredrick B. Jenne
  • Patent number: 11641745
    Abstract: Semiconductor devices and methods of manufacturing the same are provided. The semiconductor devices may have a non-volatile memory (NVM) transistor including a charge-trapping layer and a blocking dielectric, a field-effect transistor (FET) of a first type including a first gate dielectric having a first thickness, a FET of a second type including a second gate dielectric having a second thickness, and a FET of a third type including a third gate dielectric having a third thickness. In some embodiments, the first, second, and third gate dielectric includes a high dielectric constant (high-K) dielectric layer, and the first thickness is greater than the second thickness, the second thickness is greater than the third thickness. Other embodiments are also described.
    Type: Grant
    Filed: August 15, 2019
    Date of Patent: May 2, 2023
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventor: Krishnaswamy Ramkumar
  • Patent number: 11610820
    Abstract: Semiconductor devices and methods of manufacturing the same are provided. The semiconductor devices may have a memory array having two transistor (2T) memory cells, each including a non-volatile memory (NVM) transistor and a high voltage (HV) field-effect transistor (FET) as a select transistor. The devices further include a logic area in which HV FETs, input/output (I/) FETs, and low voltage (LV)/core FETs are formed thereon. Other embodiments are also described.
    Type: Grant
    Filed: June 16, 2020
    Date of Patent: March 21, 2023
    Assignee: Infineon Technologies LLC
    Inventors: Krishnaswamy Ramkumar, Venkatraman Prabhakar
  • Publication number: 20230081072
    Abstract: A semiconductor device and methods of fabricating the same are disclosed. Generally, the method includes forming a tunnel-dielectric for a memory transistor over a surface of a substrate, forming a nitride charge-trapping layer over the tunnel-dielectric, and forming a gate-dielectric for a field-effect transistor over the surface of the substrate. Forming the gate-dielectric can include performing a number of oxidation processes to form a thick gate-oxide while concurrently forming a blocking-dielectric including an oxide layer over the charge-trapping layer of the memory transistor.
    Type: Application
    Filed: December 17, 2021
    Publication date: March 16, 2023
    Applicant: Infineon Technologies LLC
    Inventors: Krishnaswamy Ramkumar, Venkatraman Prabhakar
  • Publication number: 20230074163
    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: Application
    Filed: October 20, 2022
    Publication date: March 9, 2023
    Inventors: Fredrick B Jenne, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Patent number: 11569254
    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: June 29, 2020
    Date of Patent: January 31, 2023
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Krishnaswamy Ramkumar, Bo Jin, Fredrick B. Jenne
  • Publication number: 20230023852
    Abstract: An example memory device includes a channel positioned between and electrically connecting a first diffusion region and a second diffusion region, and a tunnel dielectric layer, a multi-layer charge trapping layer, and a blocking dielectric layer disposed between the gate structure and the channel. The multi-layer charge trapping layer includes a first dielectric layer disposed abutting a second dielectric layer and an anti-tunneling layer disposed between the first and second dielectric layers. The anti-tunneling layer includes an oxide layer. The first dielectric layer includes oxygen-rich nitride and the second dielectric layer includes oxygen-lean nitride.
    Type: Application
    Filed: September 26, 2022
    Publication date: January 26, 2023
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Publication number: 20230017648
    Abstract: A semiconductor device including an oxide-nitride-oxide (ONO) structure having a multi-layer charge storing layer and methods of forming the same are provided. Generally, the method involves: (i) forming a first oxide layer of the ONO structure; (ii) forming a multi-layer charge storing layer comprising nitride on a surface of the first oxide layer; and (iii) forming a second oxide layer of the ONO structure on a surface of the multi-layer charge storing layer. Preferably, the charge storing layer comprises at least two silicon oxynitride layers having differing stoichiometric compositions of Oxygen, Nitrogen and/or Silicon. More preferably, the ONO structure is part of a silicon-oxide-nitride-oxide-silicon (SONOS) structure and the semiconductor device is a SONOS memory transistor. Other embodiments are also disclosed.
    Type: Application
    Filed: September 15, 2022
    Publication date: January 19, 2023
    Inventors: Sagy Charel Levy, Krishnaswamy Ramkumar, Fredrick Jenne, Sam G. Geha
  • Publication number: 20220359006
    Abstract: A method of fabricating a multi-level memory cell that includes the steps of forming a shallow trench isolation (STI) in a substrate, performing clean and preclean process such that top surfaces of the STI and substrate are substantially leveled, forming a tunnel dielectric using a radical oxidation process, forming upper and lower silicon oxynitride layers in which an amount of electric charge trapped represents N×analog values stored in the multi-level memory cell, N is a natural number greater than 2, forming a blocking dielectric and patterning to form a memory stack, and forming a lightly-doped drain extension (LDD) adjacent to the memory stack by angled implant such that the LDD extends at least partly under the memory stack.
    Type: Application
    Filed: May 19, 2022
    Publication date: November 10, 2022
    Applicant: Infineon Technologies LLC
    Inventors: Krishnaswamy Ramkumar, Venkatraman Prabhakar, Vineet Agrawal, Long Hinh, Santanu Kumar Samanta, Ravindra Kapre
  • Patent number: 11456365
    Abstract: An example memory device includes a channel positioned between and electrically connecting a first diffusion region and a second diffusion region, and a tunnel dielectric layer, a multi-layer charge trapping layer, and a blocking dielectric layer disposed between the gate structure and the channel. The multi-layer charge trapping layer includes a first dielectric layer disposed abutting a second dielectric layer and an anti-tunneling layer disposed between the first and second dielectric layers. The anti-tunneling layer includes an oxide layer. The first dielectric layer includes oxygen-rich nitride and the second dielectric layer includes oxygen-lean nitride.
    Type: Grant
    Filed: January 25, 2021
    Date of Patent: September 27, 2022
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Igor Polishchuk, Sagy Charel Levy, Krishnaswamy Ramkumar
  • Publication number: 20220284951
    Abstract: A semiconductor device that has a semiconductor-oxide-nitride-oxide-semiconductor (SONOS) based non-volatile memory (NVM) array including NVM cells arranged in rows and columns, in which NVM transistors of the NVM cells are configured to store N×analog values corresponding to the N×levels of their drain current (ID) or threshold voltage (VT) levels, digital-to-analog (DAC) function that receives and converts digital signals from external devices, column multiplexor (mux) function that is configured to select and combine the analog value read from the NVM cells, and analog-to-digital (ADC) function that is configured to convert analog results of the column mux function to digital values and output the digital values.
    Type: Application
    Filed: May 23, 2022
    Publication date: September 8, 2022
    Applicant: Infineon Technologies LLC
    Inventors: Venkatraman Prabhakar, Krishnaswamy Ramkumar, Vineet Agrawal, Long Hinh, Swatilekha Saha, Santanu Kumar Samanta, Michael Amundson, Ravindra M. Kapre
  • Patent number: 11367481
    Abstract: A semiconductor inference device that has a non-volatile memory (NVM) array including NVM cells arranged in rows and columns, in which each NVM cell comprises a charge trapping transistor configured to store one of N×analog values corresponding to N×levels of its drain current (ID) or threshold voltage (VT) levels, representing N×weight values for multiply accumulate (MAC) operations. The semiconductor inference device also includes digital-to-analog (DAC) function and multiplexor (mux) function configured to generate an analog MAC result based on the digital inputs converted results and the weight values read results, and analog-to-digital (ADC) function configured to convert the analog MAC result of the mux function to a digital value. Other embodiments of the semiconductor inference device and related methods and systems are also disclosed.
    Type: Grant
    Filed: May 25, 2021
    Date of Patent: June 21, 2022
    Assignee: Infineon Technologies LLC
    Inventors: Venkataraman Prabhakar, Krishnaswamy Ramkumar, Vineet Agrawal, Long Hinh, Swatilekha Saha, Santanu Kumar Samanta, Michael Amundson, Ravindra M. Kapre
  • Patent number: 11355185
    Abstract: A semiconductor device that has a silicon-oxide-nitride-oxide-silicon (SONOS) based non-volatile memory (NVM) array including charge-trapping memory cells arranged in rows and columns and configured to store one of N×analog values. Each charge-trapping memory cells may include a memory transistor including an angled lightly doped drain (LDD) implant extends at least partly under an oxide-nitride-oxide (ONO) layer of the memory transistor. The ONO layer disposed within the memory transistor and over an adjacent isolation structure has the same elevation substantially.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: June 7, 2022
    Assignee: Cypress Semiconductor Corporation
    Inventors: Krishnaswamy Ramkumar, Venkatraman Prabhakar, Vineet Agrawal, Long Hinh, Santanu Kumar Samanta, Ravindra Kapre
  • Publication number: 20220173216
    Abstract: A semiconductor device and method of manufacturing the same are provided. In one embodiment, method includes forming a first oxide layer over a substrate, forming a silicon-rich, oxygen-rich, oxynitride layer on the first oxide layer, forming a silicon-rich, nitrogen-rich, and oxygen-lean nitride layer over the oxynitride layer, and forming a second oxide layer on the nitride layer. Generally, the nitride layer includes a majority of charge traps distributed in the oxynitride layer and the nitride layer. Optionally, the method further includes forming a middle oxide layer between the oxynitride layer and the nitride layer. Other embodiments are also described.
    Type: Application
    Filed: February 18, 2022
    Publication date: June 2, 2022
    Inventors: Fredrick B. Jenne, Krishnaswamy Ramkumar
  • Publication number: 20220093773
    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: Application
    Filed: December 2, 2021
    Publication date: March 24, 2022
    Inventors: Sagy Charel Levy, Krishnaswamy Ramkumar, Fredrick Jenne, Sam G Geha
  • Patent number: 11257912
    Abstract: A semiconductor device and method of manufacturing the same are provided. In one embodiment, method includes forming a first oxide layer over a substrate, forming a silicon-rich, oxygen-rich, oxynitride layer on the first oxide layer, forming a silicon-rich, nitrogen-rich, and oxygen-lean nitride layer over the oxynitride layer, and forming a second oxide layer on the nitride layer. Generally, the nitride layer includes a majority of charge traps distributed in the oxynitride layer and the nitride layer. Optionally, the method further includes forming a middle oxide layer between the oxynitride layer and the nitride layer. Other embodiments are also described.
    Type: Grant
    Filed: September 28, 2020
    Date of Patent: February 22, 2022
    Assignee: LONGITUDE FLASH MEMORY SOLUTIONS LTD.
    Inventors: Fredrick B. Jenne, Krishnaswamy Ramkumar