Patents by Inventor Dipankar Pramanik
Dipankar Pramanik 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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Publication number: 20150179915Abstract: A dielectric for superconducting electronics (e.g., amorphous silicon, silicon oxide, or silicon nitride) is fabricated with reduced loss tangent by fluorine passivation throughout the bulk of the layer. A fluorinant (gas or plasma) is injected into a process chamber, either continuously or as a series of pulses, while the dielectric is being formed by chemical vapor deposition on a substrate. To further reduce defects, the silicon may be deposited from a silicon precursor that includes multiple co-bonded silicon atoms, such as disilane or trisilane.Type: ApplicationFiled: December 23, 2013Publication date: June 25, 2015Applicant: INTERMOLECULAR, INC.Inventors: Frank Greer, Sergey Barabash, Dipankar Pramanik, Andrew Steinbach
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Publication number: 20150179757Abstract: Metal gate high-k capacitor structures with lithography patterning are used to extract gate work function using a combinatorial workflow. Oxide terracing, together with high productivity combinatorial process flow for metal deposition can provide optimum high-k gate dielectric and metal gate solutions for high performance logic transistors. Surface treatments can be inserted at three possible steps during the formation of the MOSCAP structures. The high productivity combinatorial technique can provide an evaluation of effective work function for given high-k dielectric metal gate stacks for PMOS and NMOS transistors, which is critical in identifying and selecting the right materials.Type: ApplicationFiled: December 19, 2013Publication date: June 25, 2015Applicant: Intermoleular, Inc.Inventors: Sandip Niyogi, Dipankar Pramanik
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Publication number: 20150179916Abstract: A tunnel barrier layer in a superconducting device, such as a Josephson junction, is made from catalytically grown silicon dioxide at a low temperature (<100 C, e.g., 20-30 C) that does not facilitate oxidation or silicide formation at the superconducting electrode interface. The tunnel barrier begins as a silicon layer deposited on a superconducting electrode and covered by a thin, oxygen-permeable catalytic layer. Oxygen gas is dissociated on contact with the catalytic layer, and the resulting oxygen atoms pass through the catalytic layer to oxidize the underlying silicon. The reaction self-limits when all the silicon is converted to silicon dioxide.Type: ApplicationFiled: December 20, 2013Publication date: June 25, 2015Applicant: Intermolecular, Inc.Inventors: Dipankar Pramanik, Frank Greer, Andrew Steinbach
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Publication number: 20150179913Abstract: An amorphous silicon (a-Si) dielectric for superconducting electronics is fabricated with reduced loss tangent by fluorine passivation throughout the bulk of the layer. Complete layers or thinner sub-layers of a-Si are formed by physical vapor deposition at low temperatures (<350 C, e.g. ˜200 C) to prevent reaction with superconducting materials, then exposed to fluorine. The fluorine may be a component of a gas or plasma, or it may be a component of an interface layer. The fluorine is driven into the a-Si by heat (e.g., <350 C) or impact to passivate defects such as dangling bonds.Type: ApplicationFiled: December 20, 2013Publication date: June 25, 2015Applicant: Intermolecular, Inc.Inventors: Dipankar Pramanik, Andrew Steinbach
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Patent number: 9054032Abstract: An embodiment of the present invention sets forth an embedded resistive memory cell that includes a first stack of deposited layers, a second stack of deposited layers, a first electrode disposed under a first portion of the first stack, and a second electrode disposed under a second portion of the first stack and extending from under the second portion of the first stack to under the second stack. The second electrode is disposed proximate to the first electrode within the embedded resistive memory cell. The first stack of deposited layers includes a dielectric layer, a high-k dielectric layer disposed above the dielectric layer, and a metal layer disposed above the high-k dielectric layer. The second stack of deposited layers includes a high-k dielectric layer formed simultaneously with the high-k dielectric layer included in the first stack, and a metal layer disposed above the high-k dielectric layer.Type: GrantFiled: July 8, 2014Date of Patent: June 9, 2015Assignee: Intermolecular, Inc.Inventors: Dipankar Pramanik, Tony P. Chiang, David E Lazovsky
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Patent number: 9054307Abstract: Provided are semiconductor devices, such as resistive random access memory (ReRAM) cells, that include current limiting layers formed from alloys of transition metals. Some examples of such alloys include chromium containing alloys that may also include nickel, aluminum, and/or silicon. Other examples include tantalum and/or titanium containing alloys that may also include a combination of silicon and carbon or a combination of aluminum and nitrogen. These current limiting layers may have resistivities of at least about 1 Ohm-cm. This resistivity level is maintained even when the layers are subjected to strong electrical fields and/or high temperature processing. In some embodiments, the breakdown voltage of a current limiting layer is at least about 8V. The high resistivity of the layers allows scaling down the size of the semiconductor devices including these layers while maintaining their performance.Type: GrantFiled: June 27, 2014Date of Patent: June 9, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Yun Wang, Tony P. Chiang, Imran Hashim, Tim Minvielle, Dipankar Pramanik, Takeshi Yamaguchi
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Publication number: 20150155485Abstract: A nonvolatile resistive memory element includes an oxygen-gettering layer. The oxygen-gettering layer is formed as part of an electrode stack, and is more thermodynamically favorable in gettering oxygen than other layers of the electrode stack. The Gibbs free energy of formation (?fG°) of an oxide of the oxygen-gettering layer is less (i.e., more negative) than the Gibbs free energy of formation of an oxide of the adjacent layers of the electrode stack. The oxygen-gettering layer reacts with oxygen present in the adjacent layers of the electrode stack, thereby preventing this oxygen from diffusing into nearby silicon layers to undesirably increase an SiO2 interfacial layer thickness in the memory element and may alternately be selected to decrease such thickness during subsequent processing.Type: ApplicationFiled: February 10, 2015Publication date: June 4, 2015Inventors: Tony P. Chiang, Dipankar Pramanik, Milind Weling
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Publication number: 20150123071Abstract: Embodiments of the invention generally relate to memory devices and methods for fabricating such memory devices. In one embodiment, a method for fabricating a resistive switching memory device includes depositing a metallic layer on a lower electrode disposed on a substrate and exposing the metallic layer to an activated oxygen source while heating the substrate to an oxidizing temperature within a range from about 300° C. to about 600° C. and forming a metal oxide layer from an upper portion of the metallic layer during an oxidation process. The lower electrode contains a silicon material and the metallic layer contains hafnium or zirconium. Subsequent to the oxidation process, the method further includes heating the substrate to an annealing temperature within a range from greater than 600° C. to about 850° C. while forming a metal silicide layer from a lower portion of the metallic layer during a silicidation process.Type: ApplicationFiled: January 16, 2015Publication date: May 7, 2015Inventors: Dipankar Pramanik, Tony P. Chiang, Tim Minvielle, Takeshi Yamaguchi
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Patent number: 9023739Abstract: Methods and apparatus are described that allow the investigation of process variables used in RTP systems to be varied in a combinatorial manner across a plurality of site-isolated regions designated in the surface of a substrate. The methods and apparatus allow process variables such as power, dwell time, light source, cooling gas composition, cooling gas flow rate, reactive gas composition, reactive gas flow rate, and substrate support temperature and the like to be investigated.Type: GrantFiled: December 20, 2012Date of Patent: May 5, 2015Assignee: Intermolecular, Inc.Inventors: Ed Korczynski, Dipankar Pramanik
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Patent number: 9025360Abstract: Programming a resistive memory structure at a temperature well above the operating temperature can create a defect distribution with higher stability, leading to a potential improvement of the retention time. The programming temperature can be up to 100 C above the operating temperature. The memory chip can include embedded heaters in the chip package, allowing for heating the memory cells before the programming operations.Type: GrantFiled: December 20, 2013Date of Patent: May 5, 2015Assignee: Intermolecular, Inc.Inventors: Dipankar Pramanik, Tony P. Chiang
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Patent number: 9019744Abstract: Steering elements suitable for memory device applications can have low leakage currents at low voltages to reduce sneak current paths for non selected devices, and high leakage currents at high voltages to minimize voltage drops during device switching. In some embodiments, the steering element can include a first electrode, a second electrode, and a graded dielectric layer sandwiched between the two electrodes. The graded dielectric layer can include a varied composition from the first electrode to the second electrode. Graded energy level at the top and/or at the bottom of the band gap, which can be a result of the graded dielectric layer composition, and/or the work function of the electrodes can be configured to suppress tunneling and thermionic current in an off-state of the steering element and/or to maximize a ratio of the tunneling and thermionic currents in an on-state and in an off-state of the steering element.Type: GrantFiled: December 27, 2012Date of Patent: April 28, 2015Assignee: Intermolecular, Inc.Inventors: Sergey Barabash, Mankoo Lee, Dipankar Pramanik
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Patent number: 9012260Abstract: An internal electrical field in a resistive memory element can be formed to reduce the forming voltage. The internal electric field can be formed by incorporating one or more charged layers within the switching dielectric layer of the resistive memory element. The charged layers can include adjacent charge layers to form dipole layers. The charged layers can be formed at or near the interface of the switching dielectric layer with an electrode layer. Further, the charged layer can be oriented with lower valence substitution side towards lower work function electrode, and higher valence substitution side towards higher work function electrode.Type: GrantFiled: October 29, 2014Date of Patent: April 21, 2015Assignee: Intermolecular, Inc.Inventors: Sergey Barabash, Charlene Chen, Dipankar Pramanik
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Patent number: 9000407Abstract: A switching element for resistive-switching memory (ReRAM) provides a controllable, consistent filament break-point at an abrupt structural discontinuity between a layer of high-k high-ionicity variable-resistance (VR) material and a layer of low-k low-ionicity VR material. The high-ionicity layer may be crystalline and the low-ionicity layer may be amorphous. The consistent break-point and characteristics of the low-ionicity layer facilitate lower-power operation. The defects (e.g., oxygen or nitrogen vacancies) that constitute the filament originate either in the high-ionicity VR layer or in a source electrode. The electrode nearest to the low-ionicity layer may be intrinsically inert or may be rendered effectively inert. Some electrodes are rendered effectively inert by the creation of the low-ionicity layer over the electrode.Type: GrantFiled: May 28, 2013Date of Patent: April 7, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Yun Wang, Tony P. Chiang, Dipankar Pramanik
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Patent number: 8995166Abstract: A resistor array for multi-bit data storage without the need to increase the size of a memory chip or scale down the feature size of a memory cell contained within the memory chip is provided. The resistor array incorporates a number of discrete resistive elements to be selectively connected, in different series combinations, to at least one memory cell or memory device. In one configuration, by connecting each memory cell or device with at least one resistor array, a resistive switching layer found in the resistive switching memory element of the connected memory device is capable of being at multiple resistance states for storing multiple bits of digital information. During device programming operations, when a desired series combination of the resistive elements within the resistor array is selected, the resistive switching layer in the connected memory device can be in a desired resistance state.Type: GrantFiled: December 20, 2012Date of Patent: March 31, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Dipankar Pramanik, David E Lazovsky, Tim Minvielle, Takeshi Yamaguchi
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Patent number: 8987865Abstract: A resistor structure incorporated into a resistive switching memory cell or device to form memory devices with improved device performance and lifetime is provided. The resistor structure may be a two-terminal structure designed to reduce the maximum current flowing through a memory device. A method is also provided for making such memory device. The method includes depositing a resistor structure and depositing a variable resistance layer of a resistive switching memory cell of the memory device, where the resistor structure is disposed in series with the variable resistance layer to limit the switching current of the memory device. The incorporation of the resistor structure is very useful in obtaining desirable levels of device switching currents that meet the switching specification of various types of memory devices. The memory devices may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices.Type: GrantFiled: May 27, 2014Date of Patent: March 24, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Dipankar Pramanik, Tony P. Chiang, Mankoo Lee
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Publication number: 20150079727Abstract: Embodiments described herein provide improvements to indium-gallium-zinc oxide devices, such as amorphous IGZO thin film transistors, and methods for forming such devices. A relatively thin a-IGZO channel may be utilized. A plasma treatment chemical precursor passivation may be provided to the front-side a-IGZO interface. High-k dielectric materials may be used in the etch-stop layer at the back-side a-IGZO interface. A barrier layer may be formed above the gate electrode before the gate dielectric layer is deposited. The conventional etch-stop layer, typically formed before the source and drain regions are defined, may be replaced by a pre-passivation layer that is formed after the source and drain regions are defined and may include multiple sub-layers.Type: ApplicationFiled: September 17, 2013Publication date: March 19, 2015Applicant: Intermolecular, Inc.Inventors: Mankoo Lee, Charlene Chen, Tony P. Chiang, Dipankar Pramanik
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Patent number: 8981332Abstract: A nonvolatile resistive memory element includes an oxygen-gettering layer. The oxygen-gettering layer is formed as part of an electrode stack, and is more thermodynamically favorable in gettering oxygen than other layers of the electrode stack. The Gibbs free energy of formation (?fG°) of an oxide of the oxygen-gettering layer is less (i.e., more negative) than the Gibbs free energy of formation of an oxide of the adjacent layers of the electrode stack. The oxygen-gettering layer reacts with oxygen present in the adjacent layers of the electrode stack, thereby preventing this oxygen from diffusing into nearby silicon layers to undesirably increase an SiO2 interfacial layer thickness in the memory element and may alternately be selected to decrease such thickness during subsequent processing.Type: GrantFiled: March 15, 2013Date of Patent: March 17, 2015Assignee: Intermolecular, Inc.Inventors: Tony P. Chiang, Dipankar Pramanik, Milind Weling
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Patent number: 8975727Abstract: A resistor structure incorporated into a resistive switching memory cell with improved performance and lifetime is provided. The resistor structure may be a two-terminal structure designed to reduce the maximum current flowing through a memory cell. A method is also provided for making such a memory cell. The method includes depositing a resistor structure and depositing a variable resistance layer of a resistive switching memory cell of the memory cell, where the resistor structure is disposed in series with the variable resistance layer to limit the switching current of the memory cell. The incorporation of the resistor structure is very useful in obtaining desirable levels of switching currents that meet the switching specification of various types of memory cells. The memory cells may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices.Type: GrantFiled: December 20, 2012Date of Patent: March 10, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Yun Wang, Tony P. Chiang, Imran Hashim, Tim Minvielle, Dipankar Pramanik, Takeshi Yamaguchi
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Patent number: 8975134Abstract: A doped fullerene-based conductive material can be used as an electrode, which can contact a dielectric such as a high k dielectric. By aligning the dielectric with the band gap of the doped fullerene-based electrode, e.g., the conduction band minimum of the dielectric falls into one of the band gaps of the doped fullerene-based material, thermionic leakage through the dielectric can be reduced, since the excited electrons or holes in the electrode would need higher thermal excitation energy to overcome the band gap before passing through the dielectric layer.Type: GrantFiled: December 27, 2012Date of Patent: March 10, 2015Assignee: Intermolecular, Inc.Inventors: Sergey Barabash, Dipankar Pramanik, Xuena Zhang
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Patent number: 8975114Abstract: Embodiments of the invention generally relate to memory devices and methods for fabricating such memory devices. In one embodiment, a method for fabricating a resistive switching memory device includes depositing a metallic layer on a lower electrode disposed on a substrate and exposing the metallic layer to an activated oxygen source while heating the substrate to an oxidizing temperature within a range from about 300° C. to about 600° C. and forming a metal oxide layer from an upper portion of the metallic layer during an oxidation process. The lower electrode contains a silicon material and the metallic layer contains hafnium or zirconium. Subsequent to the oxidation process, the method further includes heating the substrate to an annealing temperature within a range from greater than 600° C. to about 850° C. while forming a metal silicide layer from a lower portion of the metallic layer during a silicidation process.Type: GrantFiled: March 14, 2013Date of Patent: March 10, 2015Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLCInventors: Dipankar Pramanik, Tony P. Chiang, Tim Minvielle, Takeshi Yamaguchi