Patents by Inventor Mihir Tendulkar
Mihir Tendulkar 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).
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Patent number: 9299926Abstract: Embodiments of the invention include a method of forming a nonvolatile memory device that contains a resistive switching memory element with improved device switching performance and lifetime, due to the addition of a current limiting component. In one embodiment, the current limiting component comprises a resistive material configured to improve the switching performance and lifetime of the resistive switching memory element. The electrical properties of the current limiting layer are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element found in the nonvolatile memory device. In one embodiment, the current limiting component comprises a tunnel oxide layer that is a current limiting material and an oxygen barrier layer that is an oxygen deficient material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.Type: GrantFiled: February 17, 2012Date of Patent: March 29, 2016Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Mihir Tendulkar, Imran Hashim, Yun Wang, Tim Minvielle, Takeshi Yamaguchi
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Patent number: 9276210Abstract: In a thin-film resistor stack (e.g. A ReRAM embedded resistor), a metallic barrier layer 1-5 nm thick protects an underlying or overlying ternary metal nitride layer from unwanted oxidation while having negligible effect on the resistance or height of the stack. For devices subjected to temperatures over 650 C after forming the stack, the metallic barrier layer may be iridium or ruthenium. For devices with temperatures kept below 650 C after forming the stack, the metallic barrier layer may be Al. The metallic barrier layer(s) and the ternary nitride layer may be formed in situ, for example by sputtering or atomic layer deposition.Type: GrantFiled: December 4, 2014Date of Patent: March 1, 2016Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventor: Mihir Tendulkar
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Patent number: 9243321Abstract: Ternary metal nitride layers suitable for thin-film resistors are fabricated by forming constituent layers of complementary components (e.g., binary nitrides of the different metals, or a binary nitride of one metal and a metallic form of the other metal), then annealing the constituent layers to interdiffuse the materials, thus forming the ternary metal nitride. The constituent layers (e.g., 2-5 nm thick) may be sputtered from binary metal nitride targets, from metal targets in a nitrogen-containing ambient, or from metal targets in an inert ambient. Optionally, a nitrogen-containing ambient may also be used for the annealing. The annealing may be 10 seconds to 10 minutes at 500-1000° C. and may also process another component on the same substrate (e.g., activate a diode).Type: GrantFiled: December 30, 2013Date of Patent: January 26, 2016Assignee: Intermolecular, Inc.Inventor: Mihir Tendulkar
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Patent number: 9231203Abstract: Provided are memory cells, such as resistive random access memory (ReRAM) cells, and methods of fabricating such cells. A cell includes an embedded resistor and resistive switching layer connected in series within the embedded resistor. The embedded resistor prevents excessive electrical currents through the resistive switching layer, especially when the resistive switching layer is switched into its low resistive state. The embedded resistor includes a stoichiometric nitride that has a bandgap of less than 2 eV. The embedded resistor is configured to maintain a substantially constant resistance throughout fabrication and operation of the cell, such as annealing the cell and subjecting the cell to forming and switching signals. The stoichiometric nitride may be one of hafnium nitride, zirconium nitride, or titanium nitride. The embedded resistor may also include a dopant, such as tantalum, niobium, vanadium, tungsten, molybdenum, or chromium.Type: GrantFiled: December 9, 2014Date of Patent: January 5, 2016Assignee: Intermolecular, Inc.Inventors: Mihir Tendulkar, Milind Weling
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Patent number: 9178142Abstract: A nonvolatile memory device and method for forming a resistive switching memory element, with improved lifetime and switching performance. A nonvolatile memory element includes resistive switching layer formed between a first and second electrode. The resistive switching layer comprises a metal oxide. One or more electrodes include a dopant material to provide the electrode with enhanced oxygen-blocking properties that maintain and control the oxygen ion content within the memory element contributing to increased device lifetime and performance.Type: GrantFiled: March 4, 2013Date of Patent: November 3, 2015Assignee: Intermolecular, Inc.Inventor: Mihir Tendulkar
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Publication number: 20150187841Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and a variable resistance layer that are interconnected in series by, for example, stacking the two. The embedded resistor prevents excessive electrical currents through the variable resistance layer thereby preventing its over-programming. The embedded resistor is configured to maintain a constant resistance during the operation of the ReRAM cell, such as applying switching currents and changing the resistance of the variable resistance layer. Specifically, the embedded resistor may be electrically broken down during fabrication of the ReRAM cell to improve the subsequent stability of the embedded resistance to electrical fields during operation of the ReRAM cell. The embedded resistor may be made from materials that allow this initial breakdown and to avoid future breakdowns, such metal silicon nitrides, metal aluminum nitrides, and metal boron nitrides.Type: ApplicationFiled: December 26, 2013Publication date: July 2, 2015Applicant: Intermolecular Inc.Inventors: Yun Wang, Mihir Tendulkar, Milind Weling
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Publication number: 20150188044Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. The ReRAM cells may include a first layer formed on a substrate. The first layer may be operable as a bottom electrode. The ReRAM cells may also include a second layer formed over the first layer. The second layer may be operable as a variable resistance layer configured to switch reversibly between at least a first resistive state and a second resistive state. The ReRAM cells may further include a third layer formed over the second layer. The third layer may have an electrical resistivity that is substantially constant. Moreover, the third layer may include a ternary metal carbide. The ReRAM cells may also include a fourth layer formed over the third layer. The fourth layer may be operable as a top electrode.Type: ApplicationFiled: December 26, 2013Publication date: July 2, 2015Applicant: Intermolecular Inc.Inventors: Yun Wang, Mihir Tendulkar
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Publication number: 20150188039Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. The ReRAM cells may include a first layer operable as a bottom electrode and a second layer operable to switch between at least a first resistive state and a second resistive state. The ReRAM cells may include a third layer including a first oxygen getter material and a fourth layer including a metal silicon nitride. The ReRAM cells may further include a fifth layer including a second oxygen getter material. The first oxygen getter material and the second oxygen getter material may be more reactive with oxygen than the metal silicon nitride. A work function of the first oxygen getter material and a work function of the second oxygen getter material may be substantially lower than a work function of the metal silicon nitride. The ReRAM cells may include a sixth layer operable as a top electrode.Type: ApplicationFiled: December 26, 2013Publication date: July 2, 2015Applicant: Intermolecular Inc.Inventors: Yun Wang, Vidyut Gopal, Mihir Tendulkar
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Publication number: 20150184283Abstract: Ternary metal nitride layers suitable for thin-film resistors are fabricated by forming constituent layers of complementary components (e.g., binary nitrides of the different metals, or a binary nitride of one metal and a metallic form of the other metal), then annealing the constituent layers to interdiffuse the materials, thus forming the ternary metal nitride. The constituent layers (e.g., 2-5 nm thick) may be sputtered from binary metal nitride targets, from metal targets in a nitrogen-containing ambient, or from metal targets in an inert ambient. Optionally, a nitrogen-containing ambient may also be used for the annealing. The annealing may be 10 seconds to 10 minutes at 500-1000° C. and may also process another component on the same substrate (e.g., activate a diode).Type: ApplicationFiled: December 30, 2013Publication date: July 2, 2015Applicant: Intermolecular Inc.Inventor: Mihir Tendulkar
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Patent number: 9030018Abstract: Provided are test vehicles for evaluating various semiconductor materials. These materials may be used for various integrated circuit components, such as embedded resistors of resistive random access memory cells. Also provided are methods of fabricating and operating these test vehicles. A test vehicle may include two stacks protruding through an insulating body. Bottom ends of these stacks may include n-doped poly-silicon and may be interconnected by a connector. Each stack may include a titanium nitride layer provided over the poly-silicon end, followed by a titanium layer over the titanium nitride layer and a noble metal layer over the titanium layer. The noble metal layer extends to the top surface of the insulating body and forms a contact surface. The titanium layer may be formed in-situ with the noble metal layer to minimize oxidation of the titanium layer, which is used as an adhesion and oxygen getter.Type: GrantFiled: September 21, 2012Date of Patent: May 12, 2015Assignee: Intermolecular, Inc.Inventors: Mihir Tendulkar, David Chi
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Patent number: 9006696Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and resistive switching layer connected in series. The embedded resistor prevents excessive electrical currents through the resistive switching layer, especially when the resistive switching layer is switched into its low resistive state, thereby preventing over-programming. The embedded resistor includes aluminum, nitrogen, and one or more additional metals (other than aluminum). The concentration of each component is controlled to achieve desired resistivity and stability of the embedded resistor. In some embodiments, the resistivity ranges from 0.1 Ohm-centimeter to 40 Ohm-centimeter and remains substantially constant while applying an electrical field of up 8 mega-Volts/centimeter to the embedded resistor. The embedded resistor may be made from an amorphous material, and the material is operable to remain amorphous even when subjected to typical annealing conditions.Type: GrantFiled: September 8, 2014Date of Patent: April 14, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Mihir Tendulkar, Randall J. Higuchi, Chien-Lan Hsueh
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Patent number: 8981329Abstract: Embodiments of the invention include a nonvolatile memory device that contains nonvolatile resistive random access memory device with improved device performance and lifetime. In some embodiments, nonvolatile resistive random access memory device includes a diode, a metal silicon nitride embedded resistor, and a resistive switching layer disposed between a first electrode layer and a second electrode layer. In some embodiments, the method of forming a resistive random access memory device includes forming a diode, forming a metal silicon nitride embedded resistor, forming a first electrode layer, forming a second electrode layer, and forming a resistive switching layer disposed between the first electrode layer and the second electrode layer.Type: GrantFiled: November 20, 2014Date of Patent: March 17, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Mihir Tendulkar, David Chi
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Publication number: 20150069319Abstract: Embodiments of the invention include a nonvolatile memory device that contains nonvolatile resistive random access memory device with improved device performance and lifetime. In some embodiments, nonvolatile resistive random access memory device includes a diode, a metal silicon nitride embedded resistor, and a resistive switching layer disposed between a first electrode layer and a second electrode layer. In some embodiments, the method of forming a resistive random access memory device includes forming a diode, forming a metal silicon nitride embedded resistor, forming a first electrode layer, forming a second electrode layer, and forming a resistive switching layer disposed between the first electrode layer and the second electrode layer.Type: ApplicationFiled: November 20, 2014Publication date: March 12, 2015Inventors: Mihir Tendulkar, David Chi
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Patent number: 8969129Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and a resistive switching layer connected in series with this resistor. The resistor is configured to prevent over-programming of the cell by limiting electrical currents through the resistive switching layer. Unlike the resistive switching layer, which changes its resistance in order to store data, the embedded resistor maintains a substantially constant resistance during operation of the cell. The embedded resistor is formed from tantalum nitride and silicon nitride. The atomic ratio of tantalum and silicon may be specifically selected to yield resistors with desired densities and resistivities as well as ability to remain amorphous when subjected to various annealing conditions. The embedded resistor may also function as a diffusion barrier layer and prevent migration of components between one of the electrodes and the resistive switching layer.Type: GrantFiled: August 20, 2014Date of Patent: March 3, 2015Assignee: Intermolecular, Inc.Inventors: Chien-Lan Hsueh, Randall J. Higuchi, Mihir Tendulkar
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Patent number: 8921154Abstract: Embodiments of the invention include a nonvolatile memory device that contains nonvolatile resistive random access memory device with improved device performance and lifetime. In some embodiments, nonvolatile resistive random access memory device includes a diode, a metal silicon nitride embedded resistor, and a resistive switching layer disposed between a first electrode layer and a second electrode layer. In some embodiments, the method of forming a resistive random access memory device includes forming a diode, forming a metal silicon nitride embedded resistor, forming a first electrode layer, forming a second electrode layer, and forming a resistive switching layer disposed between the first electrode layer and the second electrode layer.Type: GrantFiled: August 26, 2014Date of Patent: December 30, 2014Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Mihir Tendulkar, David Chi
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Publication number: 20140377931Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and resistive switching layer connected in series. The embedded resistor prevents excessive electrical currents through the resistive switching layer, especially when the resistive switching layer is switched into its low resistive state, thereby preventing over-programming. The embedded resistor includes aluminum, nitrogen, and one or more additional metals (other than aluminum). The concentration of each component is controlled to achieve desired resistivity and stability of the embedded resistor. In some embodiments, the resistivity ranges from 0.1 Ohm-centimeter to 40 Ohm-centimeter and remains substantially constant while applying an electrical field of up 8 mega-Volts/centimeter to the embedded resistor. The embedded resistor may be made from an amorphous material, and the material is operable to remain amorphous even when subjected to typical annealing conditions.Type: ApplicationFiled: September 8, 2014Publication date: December 25, 2014Inventors: Mihir Tendulkar, Randall J. Higuchi, Chien-Lan Hsueh
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Publication number: 20140363948Abstract: Embodiments of the invention include a nonvolatile memory device that contains nonvolatile resistive random access memory device with improved device performance and lifetime. In some embodiments, nonvolatile resistive random access memory device includes a diode, a metal silicon nitride embedded resistor, and a resistive switching layer disposed between a first electrode layer and a second electrode layer. In some embodiments, the method of forming a resistive random access memory device includes forming a diode, forming a metal silicon nitride embedded resistor, forming a first electrode layer, forming a second electrode layer, and forming a resistive switching layer disposed between the first electrode layer and the second electrode layer.Type: ApplicationFiled: August 26, 2014Publication date: December 11, 2014Inventors: Mihir Tendulkar, David Chi
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Publication number: 20140357046Abstract: Provided are resistive random access memory (ReRAM) cells and methods of fabricating thereof. A ReRAM cell includes an embedded resistor and a resistive switching layer connected in series with this resistor. The resistor is configured to prevent over-programming of the cell by limiting electrical currents through the resistive switching layer. Unlike the resistive switching layer, which changes its resistance in order to store data, the embedded resistor maintains a substantially constant resistance during operation of the cell. The embedded resistor is formed from tantalum nitride and silicon nitride. The atomic ratio of tantalum and silicon may be specifically selected to yield resistors with desired densities and resistivities as well as ability to remain amorphous when subjected to various annealing conditions. The embedded resistor may also function as a diffusion barrier layer and prevent migration of components between one of the electrodes and the resistive switching layer.Type: ApplicationFiled: August 20, 2014Publication date: December 4, 2014Inventors: Chien-Lan Hsueh, Randall J. Higuchi, Mihir Tendulkar
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Patent number: 8901530Abstract: Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In one embodiment, the current limiting component comprises a tunnel oxide that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.Type: GrantFiled: February 19, 2014Date of Patent: December 2, 2014Assignees: SanDisk 3D LLC, Kabushiki Kaisha ToshibaInventors: Mihir Tendulkar, Imran Hashim, Yun Wang
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Patent number: 8895949Abstract: Embodiments of the invention include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In some embodiments, the current limiting component comprises a varistor that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.Type: GrantFiled: February 10, 2014Date of Patent: November 25, 2014Assignees: SanDisk 3D LLC, Kabushiki Kaisha ToshibaInventors: Mihir Tendulkar, Imran Hashim, Yun Wang