Patents by Inventor Amitava Bose
Amitava Bose 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: 20050242371Abstract: Particularly in high current applications, impact ionization induced electron-hole pairs are generated in the drain of an MOS transistor that can cause a parasitic bipolar transistor to become destructively conductive. The holes pass through the body region of the MOS transistor, which has intrinsic resistance, to the source, which is typically held at a relatively low voltage, such as ground. The hole current causes a voltage to develop in the body region, which acts as the base. This increased base voltage is what can cause the parasitic bipolar transistor to become conductive. The likelihood of this is greatly reduced by developing a voltage between the source, which acts as the emitter, and the body region by passing the channel current through an impedance between the source and the body region. This causes the emitter voltage to increase as the base voltage is increased and thereby prevent the parasitic bipolar transistor from becoming conductive.Type: ApplicationFiled: April 30, 2004Publication date: November 3, 2005Inventors: Vishnu Khemka, Amitava Bose, Vijay Parthasarathy, Ronghua Zhu
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Publication number: 20050245020Abstract: In one embodiment, semiconductor device 10 comprises a diode which uses isolation regions (34, 16, and 13) and a plurality of dopant concentrations (30, 20, 24, and 26) which may be used to limit the parasitic current that is injected into the semiconductor substrate (12). Various biases on the isolation regions (34, 16, and 13) may be used to affect the behavior of semiconductor device (10). In addition, a conductive layer (28) may be formed overlying the junction between anode (42) and cathode (40). This conductive layer (28) may decrease the electric field in selected regions in order to increase the maximum voltage that may be applied to cathode (40).Type: ApplicationFiled: April 30, 2004Publication date: November 3, 2005Inventors: Ronghua Zhu, Amitava Bose, Vishnu Khemka, Vijay Parthasarathy
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Patent number: 6933546Abstract: A semiconductor component comprises a first semiconductor region (110, 310), a second semiconductor region (120, 320) above the first semiconductor region, a third semiconductor region (130, 330) above the second semiconductor region, a fourth semiconductor region (140, 340) above the third semiconductor region, a fifth semiconductor region (150, 350) above the second semiconductor region and at least partially contiguous with the fourth semiconductor region, a sixth semiconductor region (160, 360) above and electrically shorted to the fifth semiconductor region, and an electrically insulating layer (180, 380) above the fourth semiconductor region and the fifth semiconductor region. A junction (145, 345) between the fourth semiconductor region and the fifth semiconductor region forms a zener diode junction, which is located only underneath the electrically insulating layer. In one embodiment, a seventh semiconductor region (170) circumscribes the third, fourth, fifth, and sixth semiconductor regions.Type: GrantFiled: March 17, 2003Date of Patent: August 23, 2005Assignee: Freescale Semiconductor, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
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Patent number: 6930027Abstract: A method of manufacturing a semiconductor component includes forming a first electrically insulating layer (120) and a second electrically insulating layer (130) over a semiconductor substrate (110). The method further includes etching a first trench (140) and a second trench (150) through the first and second electrically insulating layers and into the semiconductor substrate, and etching a third trench (610) through a bottom surface of the second trench and into the semiconductor substrate. The third trench has a first portion (920) and a second portion (930) interior to the first portion. The method still further includes forming a third electrically insulating layer (910) filling the first trench and the first portion of the third trench without filling the second portion of the third trench, and also includes forming a plug layer (1010) in the second portion of the third trench.Type: GrantFiled: February 18, 2003Date of Patent: August 16, 2005Assignee: Freescale Semiconductor, Inc.Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui, Michael C. Butner
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Patent number: 6882023Abstract: A semiconductor component includes a RESURF transistor (100, 200, 300, 400, 500) that includes a first semiconductor region (110, 210, 310, 410, 510) having a first conductivity type and an electrically-floating semiconductor region (115, 215, 315, 415, 515, 545) having a second conductivity type located above the first semiconductor region. The RESURF transistor further includes a second semiconductor region (120, 220, 320, 420, 520) having the first conductivity type located above the electrically-floating semiconductor region, a third semiconductor region (130, 230) having the first conductivity type located above the second semiconductor region, and a fourth semiconductor region (140, 240, 340, 440, 540) having the second conductivity type located above the second semiconductor region.Type: GrantFiled: October 31, 2002Date of Patent: April 19, 2005Assignee: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
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Patent number: 6815780Abstract: A semiconductor component includes a semiconductor substrate (210) having a first conductivity type, a semiconductor epitaxial layer (220) having the first conductivity type located over the semiconductor substrate, a first semiconductor device (110) and a second semiconductor device (130) located in the semiconductor epitaxial layer and including, respectively, a first semiconductor region (120) and a second semiconductor region (140), both having the second conductivity type, an ohmic contact region (150) in the semiconductor epitaxial layer having the first conductivity type and located between the first and second semiconductor devices, and at least one electrically insulating trench (160, 360) located in the semiconductor epitaxial layer and circumscribing at least the first semiconductor device. The semiconductor epitaxial layer has a doping concentration lower than a doping concentration of the semiconductor substrate.Type: GrantFiled: April 15, 2003Date of Patent: November 9, 2004Assignee: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
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Publication number: 20040207047Abstract: A semiconductor component includes a semiconductor substrate (210) having a first conductivity type, a semiconductor epitaxial layer (220) having the first conductivity type located over the semiconductor substrate, a first semiconductor device (110) and a second semiconductor device (130) located in the semiconductor epitaxial layer and including, respectively, a first semiconductor region (120) and a second semiconductor region (140), both having the second conductivity type, an ohmic contact region (150) in the semiconductor epitaxial layer having the first conductivity type and located between the first and second semiconductor devices, and at least one electrically insulating trench (160, 360) located in the semiconductor epitaxial layer and circumscribing at least the first semiconductor device. The semiconductor epitaxial layer has a doping concentration lower than a doping concentration of the semiconductor substrate.Type: ApplicationFiled: April 15, 2003Publication date: October 21, 2004Applicant: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
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Publication number: 20040183098Abstract: A semiconductor component comprises a first semiconductor region (110, 310), a second semiconductor region (120, 320) above the first semiconductor region, a third semiconductor region (130, 330) above the second semiconductor region, a fourth semiconductor region (140, 340) above the third semiconductor region, a fifth semiconductor region (150, 350) above the second semiconductor region and at least partially contiguous with the fourth semiconductor region, a sixth semiconductor region (160, 360) above and electrically shorted to the fifth semiconductor region, and an electrically insulating layer (180, 380) above the fourth semiconductor region and the fifth semiconductor region. A junction (145, 345) between the fourth semiconductor region and the fifth semiconductor region forms a zener diode junction, which is located only underneath the electrically insulating layer. In one embodiment, a seventh semiconductor region (170) circumscribes the third, fourth, fifth, and sixth semiconductor regions.Type: ApplicationFiled: March 17, 2003Publication date: September 23, 2004Applicant: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose, Todd C. Roggenbauer
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Publication number: 20040161931Abstract: A method of manufacturing a semiconductor component includes forming a first electrically insulating layer (120) and a second electrically insulating layer (130) over a semiconductor substrate (110). The method further includes etching a first trench (140) and a second trench (150) through the first and second electrically insulating layers and into the semiconductor substrate, and etching a third trench (610) through a bottom surface of the second trench and into the semiconductor substrate. The third trench has a first portion (920) and a second portion (930) interior to the first portion. The method still further includes forming a third electrically insulating layer (910) filling the first trench and the first portion of the third trench without filling the second portion of the third trench, and also includes forming a plug layer (1010) in the second portion of the third trench.Type: ApplicationFiled: February 18, 2003Publication date: August 19, 2004Applicant: Motorola, Inc.Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui, Michael C. Butner
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Patent number: 6750524Abstract: A RESURF super-junction device (51) is provided which comprises a plurality of electrodes (53) disposed in a layer of a first material (61) having a first conductivity type. Each of the plurality of electrodes contains a second material (57) of a second conductivity type which is encased in a dielectric material (55).Type: GrantFiled: May 14, 2002Date of Patent: June 15, 2004Assignee: Motorola Freescale SemiconductorInventors: Vijay Parthasarthy, Vishnu Khemka, Ronghua Zhu, Amitava Bose
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Patent number: 6734524Abstract: An electronic component includes a semiconductor substrate (110), an epitaxial semiconductor layer (120, 221, 222) over the semiconductor substrate, and a semiconductor region (130, 230) in the epitaxial semiconductor layer. The epitaxial semiconductor layer has an upper surface (123). A first portion (121) of the epitaxial semiconductor layer is located below the semiconductor region, and a second portion (122) of the epitaxial semiconductor layer is located above the semiconductor region. The semiconductor substrate and the first portion of the epitaxial semiconductor layer have a first conductivity type, and the semiconductor region has a second conductivity type. At least one electrically insulating trench (140, 240) extends from the upper surface of the epitaxial semiconductor layer into at least a portion of the semiconductor region. The semiconductor substrate has a doping concentration higher than a doping concentration of the first portion of the epitaxial semiconductor layer.Type: GrantFiled: December 31, 2002Date of Patent: May 11, 2004Assignee: Motorola, Inc.Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose, Todd Roggenbauer, Paul Hui
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Publication number: 20040084744Abstract: A semiconductor component includes a RESURF transistor (100, 200, 300, 400, 500) that includes a first semiconductor region (110, 210, 310, 410, 510) having a first conductivity type and an electrically-floating semiconductor region (115, 215, 315, 415, 515, 545) having a second conductivity type located above the first semiconductor region. The RESURF transistor further includes a second semiconductor region (120, 220, 320, 420, 520) having the first conductivity type located above the electrically-floating semiconductor region, a third semiconductor region (130, 230) having the first conductivity type located above the second semiconductor region, and a fourth semiconductor region (140, 240, 340, 440, 540) having the second conductivity type located above the second semiconductor region.Type: ApplicationFiled: October 31, 2002Publication date: May 6, 2004Applicant: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
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Patent number: 6703895Abstract: An embodiment of a method of redistributing power in a semiconductor component includes varying a saturation current between a drain terminal (330) and a source terminal (320) of a field effect transistor (FET) (200, 500). The FET is at least a portion of the semiconductor component. The threshold voltage of the FET is maintained substantially constant across the FET while the drain-to-source saturation current per unit area is varied across the FET. In one embodiment, the drain-to-source saturation current per unit area is varied such that it is lower at a center of the FET than at a periphery of the FET. In particular embodiments, the drain-to-source saturation current per unit area may be varied across the FET by changing one or more of the gate-to-source voltage, the channel length, the channel width, the gate oxide thickness, and the channel mobility across the FET.Type: GrantFiled: September 26, 2002Date of Patent: March 9, 2004Assignee: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
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Patent number: 6693339Abstract: A semiconductor component includes a first semiconductor region (110, 210) having a first conductivity type and a second semiconductor region (120, 220) above the first semiconductor region and having a second conductivity type. The semiconductor component further comprises a third semiconductor region (130, 230) above the second semiconductor region and having the first conductivity type, a fourth semiconductor region (140, 240) above the third semiconductor region and having the second conductivity type, a fifth semiconductor region (150, 250) above the third semiconductor region and having the first conductivity type, a sixth semiconductor region (160, 260) substantially enclosed within the fifth semiconductor region and having the second conductivity type, and a seventh semiconductor region (170, 270) above the first semiconductor region and having the second conductivity type.Type: GrantFiled: March 14, 2003Date of Patent: February 17, 2004Assignee: Motorola, Inc.Inventors: Vishnu Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
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Publication number: 20030214009Abstract: A RESURF super-junction device (51) is provided which comprises a plurality of electrodes (53) disposed in a layer of a first material (61) having a first conductivity type. Each of the plurality of electrodes contains a second material (57) of a second conductivity type which is encased in a dielectric material (55).Type: ApplicationFiled: May 14, 2002Publication date: November 20, 2003Applicant: Motorola Inc.Inventors: Vijay Parthasarathy, Vishnu Khemka, Ronghua Zhu, Amitava Bose
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Patent number: 6573562Abstract: A semiconductor component includes a semiconductor substrate (110) having first and second portions (111, 112) with a first conductivity type, a transistor (120) at least partially located in the semiconductor substrate, and a switching circuit (150, 350, 650, 850). The transistor includes (i) a first doped region in the first portion of the semiconductor substrate and having the first conductivity type (ii) a terminal, which includes a second doped region having a second conductivity type and located in the first portion of the semiconductor substrate and over the first doped region, and (iii) a third doped region having the second conductivity type and located in the semiconductor substrate below the first portion of the semiconductor substrate and above the second portion of the semiconductor substrate. The switching circuit is electrically coupled to the third doped region to adjust the bias of the third doped region.Type: GrantFiled: October 31, 2001Date of Patent: June 3, 2003Assignee: Motorola, Inc.Inventors: Vijay Parthasarathy, Ronghua Zhu, Vishnu K. Khemka, Amitava Bose
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Publication number: 20030080381Abstract: A semiconductor component includes a semiconductor substrate (110) having first and second portions (111, 112) with a first conductivity type, a transistor (120) at least partially located in the semiconductor substrate, and a switching circuit (150, 350, 650, 850). The transistor includes (i) a first doped region in the first portion of the semiconductor substrate and having the first conductivity type (ii) a terminal, which includes a second doped region having a second conductivity type and located in the first portion of the semiconductor substrate and over the first doped region, and (iii) a third doped region having the second conductivity type and located in the semiconductor substrate below the first portion of the semiconductor substrate and above the second portion of the semiconductor substrate. The switching circuit is electrically coupled to the third doped region to adjust the bias of the third doped region.Type: ApplicationFiled: October 31, 2001Publication date: May 1, 2003Inventors: Vijay Parthasarathy, Ronghua Zhu, Vishnu K. Khemka, Amitava Bose
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Patent number: 6528849Abstract: A MOSFET includes a source region, a first channel region proximate to the source region, a first gate region adjacent to the first base region, a drain region, a second channel region proximate to the drain region, and a second gate region adjacent to the second channel region. A first channel is formed within the first channel region in dependence upon a first voltage applied to the first gate region with respect to at least a first portion of the source region, and a second channel is formed within the second channel region in dependence upon a second voltage applied to the second gate region with respect to at least a second portion of the drain region. The MOSFET further includes a drift region coupled between the first channel region and the second channel region, where the drift region includes a set of alternating columns, each of which is also coupled between the first base region and the second base region.Type: GrantFiled: August 31, 2000Date of Patent: March 4, 2003Assignee: Motorola, Inc.Inventors: Vishnu K. Khemka, Vijay Parthasarathy, Ronghua Zhu, Amitava Bose
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Patent number: 5492858Abstract: Disclosed is a method of planarizing the surface of a silicon wafer in integrated circuit manufacture where shallow trench isolation techniques are employed. The etched trenches are first coated with a silicon nitride protective liner before the trenches and active area mesas are conformally coated with a layer of silicon oxide. The conformal oxide then is steam annealed to densify the conformal oxide, and then the surface of the silicon wafer is etched and polished back down to the tops of the active area mesas, to form a substantially planar surface.Type: GrantFiled: April 20, 1994Date of Patent: February 20, 1996Assignee: Digital Equipment CorporationInventors: Amitava Bose, Marion M. Garver, Andre I. Nasr, Steven S. Cooperman