Patents by Inventor Mahendra Pakala

Mahendra Pakala 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: 20240138147
    Abstract: A method includes obtaining a base structure of a three-dimensional (3D) memory device, forming, on the base structure, a blocking layer including a high-k dielectric material, and forming, on the blocking layer, a wordline for the 3D memory device including molybdenum using an atomic layer deposition (ALD) process.
    Type: Application
    Filed: October 12, 2023
    Publication date: April 25, 2024
    Inventors: Jaesoo Ahn, Jose Alexandro Romero, Kunal Bhatnagar, Mahendra Pakala
  • Publication number: 20230389441
    Abstract: Embodiments of the present disclosure generally include spin-orbit torque magnetoresistive random-access memory (SOT-MRAM) devices and methods of manufacture thereof. The SOT-MRAM devices described herein include an SOT layer laterally aligned with a magnetic tunnel junction (MTJ) stack and formed over a trench in an interconnect. Thus, the presence of the SOT layer outside the area of the MTJ stack is eliminated, and electric current passes from the interconnect to the SOT layer by SOT-interconnect overlap. The devices and methods described herein reduce the formation of shunting current and enable the MTJ to self-align with the SOT layer in a single etching process.
    Type: Application
    Filed: August 8, 2023
    Publication date: November 30, 2023
    Applicant: Applied Materials, Inc.
    Inventors: Minrui YU, Wenhui WANG, Jaesoo AHN, Jong Mun KIM, Sahil PATEL, Lin XUE, Chando PARK, Mahendra PAKALA, Chentsau Chris YING, Huixiong DAI, Christopher S. NGAI
  • Patent number: 11818959
    Abstract: Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for hybrid (or called integrated) spin-orbit-torque magnetic spin-transfer-torque magnetic random access memory (SOT-STT MRAM) applications. In one embodiment, the method includes one or more magnetic tunnel junction structures disposed on a substrate, the magnetic tunnel junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer, a spin orbit torque (SOT) layer disposed on the magnetic tunnel junction structure, and a back end structure disposed on the spin orbit torque (SOT) layer.
    Type: Grant
    Filed: July 19, 2021
    Date of Patent: November 14, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Hsin-wei Tseng, Chando Park, Jaesoo Ahn, Lin Xue, Mahendra Pakala
  • Patent number: 11764058
    Abstract: Methods of reducing wafer bowing in 3D DRAM devices are described using a 3-color process. A plurality of film stacks are formed on a substrate surface, each of the film stacks comprises two doped SiGe layers having different dopant amounts and/or Si:Ge ratios and a doped silicon layer. 3D DRAM devices are also described.
    Type: Grant
    Filed: September 28, 2021
    Date of Patent: September 19, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Arvind Kumar, Mahendra Pakala, Ellie Y. Yieh, John Tolle, Thomas Kirschenheiter, Anchuan Wang, Zihui Li
  • Patent number: 11723283
    Abstract: Embodiments of the present disclosure generally include spin-orbit torque magnetoresistive random-access memory (SOT-MRAM) devices and methods of manufacture thereof. The SOT-MRAM devices described herein include an SOT layer laterally aligned with a magnetic tunnel junction (MTJ) stack and formed over a trench in an interconnect. Thus, the presence of the SOT layer outside the area of the MTJ stack is eliminated, and electric current passes from the interconnect to the SOT layer by SOT-interconnect overlap. The devices and methods described herein reduce the formation of shunting current and enable the MTJ to self-align with the SOT layer in a single etching process.
    Type: Grant
    Filed: May 11, 2020
    Date of Patent: August 8, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Minrui Yu, Wenhui Wang, Jaesoo Ahn, Jong Mun Kim, Sahil Patel, Lin Xue, Chando Park, Mahendra Pakala, Chentsau Chris Ying, Huixiong Dai, Christopher S. Ngai
  • Patent number: 11621393
    Abstract: Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate for MRAM applications. In one embodiment, a magnetic tunnel junction (MTJ) device structure includes a junction structure disposed on a substrate, the junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer, a dielectric capping layer disposed on the junction structure, a metal capping layer disposed on the junction structure, and a top buffer layer disposed on the metal capping layer.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: April 4, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Lin Xue, Chando Park, Chi Hong Ching, Jaesoo Ahn, Mahendra Pakala
  • Publication number: 20230102558
    Abstract: Methods of reducing wafer bowing in 3D DRAM devices are described using a 3-color process. A plurality of film stacks are formed on a substrate surface, each of the film stacks comprises two doped SiGe layers having different dopant amounts and/or Si:Ge ratios and a doped silicon layer. 3D DRAM devices are also described.
    Type: Application
    Filed: September 28, 2021
    Publication date: March 30, 2023
    Applicant: Applied Materials, Inc.
    Inventors: Arvind Kumar, Mahendra Pakala, Ellie Y. Yieh, John Tolle, Thomas Kirschenheiter, Anchuan Wang, Zihui Li
  • Patent number: 11552244
    Abstract: Embodiments of magnetic tunnel junction (MTJ) structures discussed herein employ seed layers of one or more layer of chromium (Cr), NiCr, NiFeCr, RuCr, IrCr, or CoCr, or combinations thereof. These seed layers are used in combination with one or more pinning layers, a first pinning layer in contact with the seed layer can contain a single layer of cobalt, or can contain cobalt in combination with bilayers of cobalt and platinum (Pt), iridium (Ir), nickel (Ni), or palladium (Pd), The second pinning layer can be the same composition and configuration as the first, or can be of a different composition or configuration. The MTJ stacks discussed herein maintain desirable magnetic properties subsequent to high temperature annealing.
    Type: Grant
    Filed: March 5, 2021
    Date of Patent: January 10, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Lin Xue, Chi Hong Ching, Rongjun Wang, Mahendra Pakala
  • Patent number: 11522126
    Abstract: A film stack for a magnetic tunnel comprises a substrate, a magnetic reference layer disposed over the substrate, and a tunnel barrier layer disposed over the magnetic reference layer. The film stack further comprises a magnetic storage layer disposed over the tunnel barrier layer, and a capping layer disposed over the magnetic storage layer. Further, the film stack comprises at least one protection layer disposed between the magnetic reference layer and the tunnel barrier layer and disposed between the magnetic storage layer and the capping layer. Additionally, a material forming the at least one protection layer differs from at least one of a material forming the magnetic reference layer and a material forming the magnetic storage layer.
    Type: Grant
    Filed: October 14, 2019
    Date of Patent: December 6, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Lin Xue, Jaesoo Ahn, Sahil Patel, Chando Park, Mahendra Pakala
  • Patent number: 11456301
    Abstract: Embodiments of the present disclosure generally relate to a storage device. More specifically, embodiments described herein generally relate to a dynamic random-access memory and the method of making thereof. In one embodiment, a cell array includes at least an active region and a field region adjacent to the active region. The active region includes at least one trench, a dielectric layer disposed in the trench, a first conformal layer disposed on the dielectric layer, and a conductive material disposed on the first conformal layer. The field region includes a trench, a dielectric layer disposed in the trench, a second conformal layer disposed on the dielectric layer, and a conductive material disposed on the second conformal layer. The second conformal layer has a different composition than the first conformal layer.
    Type: Grant
    Filed: July 16, 2020
    Date of Patent: September 27, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Arvind Kumar, Mahendra Pakala, Sanjeev Manhas, Satendra Kumar Gautam
  • Patent number: 11374170
    Abstract: Embodiments of the disclosure relate to methods for fabricating structures used in memory devices. More specifically, embodiments of the disclosure relate to methods for fabricating MTJ structures in memory devices. In one embodiment, the method includes forming a MTJ structure, depositing a encapsulating layer on a top and sides of the MTJ structure, depositing a dielectric material on the encapsulating layer, removing the dielectric material and the encapsulating layer disposed on the top of the MTJ structure by a chemical mechanical planarization (CMP) process to expose the top of the MTJ structure, and depositing a contact layer on the MTJ structure. The method utilizes a CMP process to expose the top of the MTJ structure instead of an etching process, which avoids damaging the MTJ structure and leads to improved electrical contact between the MTJ structure and the contact layer.
    Type: Grant
    Filed: September 25, 2018
    Date of Patent: June 28, 2022
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Lin Xue, Jaesoo Ahn, Hsin-wei Tseng, Mahendra Pakala
  • Patent number: 11374165
    Abstract: A process sequence is provided to provide an ultra-smooth (0.2 nm or less) bottom electrode surface for depositing magnetic tunnel junctions thereon. In one embodiment, the sequence includes forming a bottom electrode pad through bulk layer deposition followed by patterning and etching. Oxide is then deposited over the formed bottom electrode pads and polished back to expose the bottom electrode pads. A bottom electrode buff layer is then deposited thereover following a pre-clean operation. The bottom electrode buff layer is then exposed to a chemical mechanical polishing process to improve surface roughness. An magnetic tunnel junction deposition is then performed over the bottom electrode buff layer.
    Type: Grant
    Filed: March 5, 2020
    Date of Patent: June 28, 2022
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Lin Xue, Sajjad Amin Hassan, Mahendra Pakala, Jaesoo Ahn
  • Publication number: 20220115439
    Abstract: Implementations of the present disclosure generally relate to a memory device. More specifically, implementations described herein generally relate to a SOT-MRAM. The SOT-MRAM includes a memory cell having a magnetic storage layer disposed side by side and in contact with a SOT layer. The side by side magnetic storage layer and the SOT layer can achieve the switching of the magnetic storage layer by reversing the direction of the electrical current flowing through the SOT layer without any additional conditions.
    Type: Application
    Filed: January 16, 2020
    Publication date: April 14, 2022
    Inventors: Lin XUE, Chando PARK, Jaesoo AHN, Hsin-wei TSENG, Mahendra PAKALA
  • Patent number: 11264460
    Abstract: The present disclosure provides methods for forming a channel structure in a film stack for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, and a channel structure formed in the film stack, wherein the channel structure is filled with a channel layer and a protective blocking layer, wherein the channel layer has a gradient dopant concentration along a vertical stacking of the film stack.
    Type: Grant
    Filed: July 23, 2019
    Date of Patent: March 1, 2022
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Arvind Kumar, Sanjeev Manhas, Mahendra Pakala, Ellie Y. Yieh
  • Patent number: 11251364
    Abstract: Embodiments herein provide film stacks that include a buffer layer; a synthetic ferrimagnet (SyF) coupling layer; and a capping layer, wherein the capping layer comprises one or more layers, and wherein the capping layer, the buffer layer, the SyF coupling layer, or a combination thereof, is not fabricated from Ru.
    Type: Grant
    Filed: January 27, 2020
    Date of Patent: February 15, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Lin Xue, Chi Hong Ching, Jaesoo Ahn, Mahendra Pakala, Rongjun Wang
  • Patent number: 11245069
    Abstract: Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for spin-transfer-torque magnetoresistive random access memory (STT-MRAM) applications. In one embodiment, the method includes patterning a film stack having a tunneling barrier layer disposed between a magnetic reference layer and a magnetic storage layer disposed on a substrate to remove a portion of the film stack from the substrate until an upper surface of the substrate is exposed, forming a sidewall passivation layer on sidewalls of the patterned film stack and subsequently performing a thermal annealing process to the film stack.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: February 8, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Lin Xue, Jaesoo Ahn, Mahendra Pakala, Chi Hong Ching, Rongjun Wang
  • Patent number: 11239086
    Abstract: Embodiments described herein relate to substrate processing methods. More specifically, embodiments of the disclosure provide for an MRAM back end of the line integration process which utilizes a zero mark for improved patterning alignment. In one embodiment, the method includes fabricating a substrate having at least a bottom contact and a via extending from the bottom contact in a first region and etching a zero mark in the substrate in a second region apart from the first region. The method also includes depositing a touch layer over the substrate in the first region and the second region, depositing a memory stack over the touch layer in the first region and the second region, and depositing a hardmask over the memory stack layer in the first region and the second region.
    Type: Grant
    Filed: April 26, 2019
    Date of Patent: February 1, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Hsin-wei Tseng, Mahendra Pakala, Lin Xue, Jaesoo Ahn, Sajjad Amin Hassan
  • Publication number: 20220013716
    Abstract: Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for spin-transfer-torque magnetoresistive random access memory (STT-MRAM) applications. In one example, a film stack utilized to form a magnetic tunnel junction structure on a substrate includes a pinned layer disposed on a substrate, wherein the pinned layer comprises multiple layers including at least one or more of a Co containing layer, Pt containing layer, Ta containing layer, an Ru containing layer, an optional structure decoupling layer disposed on the pinned magnetic layer, a magnetic reference layer disposed on the optional structure decoupling layer, a tunneling barrier layer disposed on the magnetic reference layer, a magnetic storage layer disposed on the tunneling barrier layer, and a capping layer disposed on the magnetic storage layer.
    Type: Application
    Filed: September 27, 2021
    Publication date: January 13, 2022
    Inventors: Lin XUE, Jaesoo AHN, Mahendra PAKALA, Chi Hong CHING, Rongjun WANG
  • Publication number: 20220005831
    Abstract: Embodiments of the present disclosure provide an apparatus and methods for forming stair-like structures with accurate profiles and dimension control for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, an opening formed in the film stack, wherein the opening is filled with a channel layer and a center filling layer, and a protective liner layer disposed between the conductive structure and the channel layer.
    Type: Application
    Filed: September 20, 2021
    Publication date: January 6, 2022
    Inventors: Jaesoo AHN, Thomas KWON, Mahendra PAKALA
  • Publication number: 20210351344
    Abstract: Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for hybrid (or called integrated) spin-orbit-torque magnetic spin-transfer-torque magnetic random access memory (SOT-STT MRAM) applications. In one embodiment, the method includes one or more magnetic tunnel junction structures disposed on a substrate, the magnetic tunnel junction structure comprising a first ferromagnetic layer and a second ferromagnetic layer sandwiching a tunneling barrier layer, a spin orbit torque (SOT) layer disposed on the magnetic tunnel junction structure, and a back end structure disposed on the spin orbit torque (SOT) layer.
    Type: Application
    Filed: July 19, 2021
    Publication date: November 11, 2021
    Applicants: Applied Materials, Inc., Applied Materials, Inc.
    Inventors: Hsin-wei TSENG, Chando PARK, Jaesoo AHN, Lin XUE, Mahendra PAKALA