Varactor Diode (epo) Patents (Class 257/E27.049)
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Patent number: 10608123Abstract: An integrated circuit formed with a process that enables multiple types of gate stacks improves a quality factor of metal oxide semiconductor (MOS) varactors at the device level. In one instance, the integrated circuit includes multiple first type transistors having a first gate stack with a first resistance and multiple second type transistors having a second gate stack with a second resistance that is higher than the first resistance. The integrated circuit also includes a metal oxide semiconductor varactor having the first gate stack with the first resistance.Type: GrantFiled: September 19, 2017Date of Patent: March 31, 2020Assignee: QUALCOMM IncorporatedInventor: Phanikumar Konkapaka
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Patent number: 9735676Abstract: Resonant power converters and inverters comprising a self-oscillating feedback loop coupled from a switch output to a control input of a switching network comprising one or more semiconductor switches (S1, S2). The self-oscillating feedback loop sets a switching frequency of the power converter (100) and comprises a first intrinsic switch capacitance (CGD) coupled between a switch output and a control input of the switching network and a first inductor (LG). The first inductor (LG) is coupled in-between a first bias voltage source and the control input of the switching network and has a substantially fixed inductance. The first bias voltage source is configured to generate an adjustable bias voltage (VBias) applied to the first inductor (LG). The output voltage (V0UT) of the power converter (100) is controlled in a flexible and rapid manner by controlling the adjustable bias voltage (VBias).Type: GrantFiled: October 29, 2013Date of Patent: August 15, 2017Assignee: Danmarks Tekniske UniversitetInventors: Mickey P Madsen, Jeppe Arnsdorf Pedersen
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Patent number: 9697762Abstract: In a display device including a driver that drives load lines in an electro-optical panel through capacitor charge redistribution, load capacitance among the load lines of the electro-optical panel differs depending on parasitic capacitance of a board on which the load lines are mounted, the type of the panel, and so on, and the accuracy of driving voltages drops due to such variations. The driver is provided with a adjusting capacitance group that corrects variation in load capacitance, and by adjusting a driving capacitance on the driver side, a ratio with the load capacitance is increased and accuracy of a post-driving potential is increased.Type: GrantFiled: September 30, 2015Date of Patent: July 4, 2017Assignee: SEIKO EPSON CORPORATIONInventor: Akira Morita
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Patent number: 9136061Abstract: A varactor comprises a substrate having sets of gate units each having parallel gate strips. The gate units are located such that the gate strips of neighboring gate units are oriented transverse to each other. An electrically conducting gate connection layer comprises gate connection units comprising parallel gate connection strips located over the gate strips, and a cathode connection frame around each of the gate connection units. A first electrically conductive anode layer comprises first layer anode strips located parallel to the gate connection strips and connected to alternate gate connection strips, and a first anode connection frame connected to the anode strips. A second electrically conductive anode layer comprises anode strips located parallel to the gate connection strips and connected to opposite alternate gate connection strips, and a second anode connection frame connected to the second layer anode strips.Type: GrantFiled: July 29, 2013Date of Patent: September 15, 2015Assignee: NXP, B.V.Inventors: Olivier Tesson, Laure Rolland du Roscoat
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Patent number: 8980708Abstract: A complementary back end of line (BEOL) capacitor (CBC) structure includes a metal oxide metal (MOM) capacitor structure. The MOM capacitor structure is coupled to a first upper interconnect layer of an interconnect stack of an integrated circuit (IC) device. The MOM capacitor structure includes at least one lower interconnect layer of the interconnect stack. The CBC structure may also include a second upper interconnect layer of the interconnect stack coupled to the MOM capacitor structure. The CBC structure also includes at least one metal insulator metal (MIM) capacitor layer between the first upper interconnect layer and the second upper interconnect layer. In addition, CBC structure may also include a MIM capacitor structure coupled to the MOM capacitor structure. The MIM capacitor structure includes a first capacitor plate having at least a portion of the first upper interconnect layer, and a second capacitor plate having at least a portion of the MIM capacitor layer(s).Type: GrantFiled: February 19, 2013Date of Patent: March 17, 2015Assignee: QUALCOMM IncorporatedInventors: John J. Zhu, Bin Yang, P R Chidambaram, Lixin Ge, Jihong Choi
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Patent number: 8878340Abstract: Devices or systems that include a composite thermal capacitor disposed in thermal communication with a hot spot of the device, methods of dissipating thermal energy in a device or system, and the like, are provided herein. In particular, the device includes a composite thermal capacitor including a phase change material and a high thermal conductivity material in thermal communication with the phase change material. The high thermal conductivity material is also in thermal communication with an active regeneration cooling device. The heat from the composite thermal capacitor is dissipated by the active regeneration cooling device.Type: GrantFiled: August 30, 2013Date of Patent: November 4, 2014Assignee: Georgia Tech Research CorporationInventors: Andrei G. Fedorov, Craig Green, Yogendra Joshi
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Patent number: 8796809Abstract: A varactor diode includes a contact layer having a first conductivity type, a voltage blocking layer having the first conductivity and a first net doping concentration on the contact layer, a blocking junction on the voltage blocking layer, and a plurality of discrete doped regions in the voltage blocking layer and spaced apart from the carrier injection junction. The plurality of discrete doped regions have the first conductivity type and a second net doping concentration that is higher than the first net doping concentration, and the plurality of discrete doped regions are configured to modulate the capacitance of the varactor diode as a depletion region of the varactor diode expands in response to a reverse bias voltage applied to the blocking junction. Related methods of forming a varactor diode are also disclosed.Type: GrantFiled: September 8, 2008Date of Patent: August 5, 2014Assignee: Cree, Inc.Inventor: Christopher Harris
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Patent number: 8502348Abstract: The present invention provides a differential varactor device including a substrate having a first conductive type, a well having a second conductive type, five doped regions having the second conductive type, a first gate, a second gate, a third gate, and a fourth gate. The well is disposed in the substrate, and the doped regions are disposed in the well and arranged along a direction. The first gate, the second gate, the third gate and the fourth gate are respectively disposed on the well between any two of the adjacent doped regions, and are arranged sequentially along the direction.Type: GrantFiled: July 8, 2011Date of Patent: August 6, 2013Assignee: United Microelectronics Corp.Inventors: Yue-Shiun Lee, Cheng-Hsiung Chen, Meng-Fan Wang
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Patent number: 8492823Abstract: Disclosed is a semiconductor structure, which includes a non-planar varactor having a geometrically designed depletion zone with a taper, as to provide improved Cmax/Cmin with low series resistance. Because of the taper, the narrowest portion of the depletion zone can be designed to be fully depleted, while the remainder of the depletion zone is only partially depleted. The fabrication of semiconductor structure may follow that of standard FinFET process, with a few additional or different steps. These additional or different steps may include formation of a doped trapezoidal (or triangular) shaped silicon mesa, growing/depositing a gate dielectric, forming a gate electrode over a portion of the mesa, and forming a highly doped contact region in the mesa where it is not covered by the gate electrode.Type: GrantFiled: May 28, 2009Date of Patent: July 23, 2013Assignee: International Business Machines CorporationInventor: Edward J. Nowak
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Patent number: 8450832Abstract: Large tuning range junction varactor includes first and second junction capacitors coupled in parallel between first and second varactor terminals. First and second plates of the capacitors are formed by three alternating doped regions in a substrate. The first and third doped regions are of the same type sandwiching the second doped region of the second type. A first input terminal is coupled to the first and third doped regions and a second terminal is coupled to the second doped region. At the interfaces of the doped regions are first and second depletion regions whose width can be varied by varying the voltage across the terminals from zero to full reverse bias.Type: GrantFiled: April 5, 2007Date of Patent: May 28, 2013Assignee: GLOBALFOUNDRIES Singapore Pte. Ltd.Inventors: Manju Sarkar, Purakh Raj Verma
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Patent number: 8450827Abstract: Apparatus and methods for a MOS varactor structure are disclosed An apparatus is provided, comprising an active area defined in a portion of a semiconductor substrate; a doped well region in the active area extending into the semiconductor substrate; at least two gate structures disposed in parallel over the doped well region; source and drain regions disposed in the well region formed on opposing sides of the gate structures; a gate connector formed in a first metal layer overlying the at least two gate structures and electrically coupling the at least two gate structures; source and drain connectors formed in a second metal layer and electrically coupled to the source and drain regions; and interlevel dielectric material separating the source and drain connectors in the second metal layer from the gate connector formed in the first metal layer. Methods for forming the structure are disclosed.Type: GrantFiled: January 25, 2011Date of Patent: May 28, 2013Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Chi-Feng Huang, Chia-Chung Chen
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Patent number: 8304856Abstract: A serially-connected diode pair made of diodes having a high withstand voltage and a low on-resistance is formed based on a high withstand voltage vertical PNP bipolar transistor process technology. Two of the diode pairs are connected in parallel to form a bridge so that there is formed a high-efficiency full-wave rectifier circuit that is free from a leakage current due to a parasitic transistor. The serially-connected diode pair is formed by connecting a diode composed of a P type semiconductor substrate, that makes an anode, and an N type buried layer, that makes a cathode, and a diode composed of a P+ type conductive layer, that makes an anode, and an N type epitaxial layer, that makes a cathode, in series with an electrode AC1.Type: GrantFiled: September 13, 2010Date of Patent: November 6, 2012Assignees: Sanyo Semiconductor Co., Ltd., Sanyo Semiconductor Manufacturing Co., Ltd., Semiconductor Components Industries, LLCInventors: Keiji Mita, Yasuhiro Tamada, Masao Takahashi, Takao Maruyama
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Patent number: 8217489Abstract: A nonvolatile memory apparatus includes a first electrode, a second electrode, a variable resistance layer, a resistance value of the variable resistance layer reversibly varying between a plurality of resistance states based on an electric signal applied between the electrodes. The variable resistance layer includes at least a tantalum oxide, and is configured to satisfy 0<x<2.5 when the tantalum oxide is represented by TaOx; and wherein when a resistance value between the electrodes is in the low-resistance state is RL, a resistance value between the electrodes is in the high-resistance state is RH, and a resistance value of a portion other than the variable resistance layer in a current path connecting a first terminal to a second terminal via the first electrode, the variable resistance layer and the second electrode, is R0, R0 satisfies RL<R0.Type: GrantFiled: September 27, 2011Date of Patent: July 10, 2012Assignee: Panasonic CorporationInventors: Koichi Osano, Satoru Fujii, Shunsaku Muraoka
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Patent number: 8115281Abstract: A high-Q differential varactor includes reduced inner spacing dimensions between differential fingers.Type: GrantFiled: May 20, 2008Date of Patent: February 14, 2012Assignee: Atmel CorporationInventors: Adam H. Pawlikiewicz, Samir el Rai
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Patent number: 8053866Abstract: An improved varactor diode (20, 50) having first (45) and second (44) terminals is obtained by providing a substrate (22, 52) having a first surface (21, 51) in which are formed isolation regions (28, 58) separating first (23, 53) and second (25, 55) parts of the diode (20, 50). A varactor junction (40, 70) is formed in the first part (23, 53) and having a first side (35, 66) coupled to the first terminal (45) and a second side (34, 54) coupled to the second terminal (44) via a sub-isolation buried layer (SIBL) region (26, 56) extending under the bottom (886) and partly up the sides (885) of the isolation regions (28, 58) to a further doped region (30, 32; 60, 62) ohmically connected to the second terminal (44). The first part (36, 66) does not extend to the SIBL region (26, 56). The varactor junction (40, 70) desirably comprises a hyper-abrupt doped region (34, 54).Type: GrantFiled: August 6, 2009Date of Patent: November 8, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Pamela J. Welch, Wen Ling M. Huang, David G. Morgan, Hernan A. Reuda, Vishal P. Trivedi
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Patent number: 8022507Abstract: An improved varactor diode is obtained by providing a substrate having a first surface and in which are formed a first N region having a first peak dopant concentration located at a first depth beneath the surface, and a first P region having a second peak dopant concentration greater than the first peak dopant concentration located at a second depth beneath the surface less than the first depth, and a second P region having a third peak dopant concentration greater than the second peak dopant concentration and located at a third depth at or beneath the surface less than the second depth, so that the first P region provides a retrograde doping profile whose impurity concentration increases with distance from the inward edge of the second P region up to the second peak dopant concentration.Type: GrantFiled: February 25, 2011Date of Patent: September 20, 2011Assignee: Freescale Semiconductor, Inc.Inventor: Vishal P. Trivedi
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Patent number: 7952131Abstract: Large tuning range junction varactor includes first and second junction capacitors coupled in parallel between first and second varactor terminals. First and second plates of the capacitors are formed by three alternating doped regions in a substrate. The second and third doped regions are of the same type sandwiching the first doped region of the second type. A first varactor terminal is coupled to the second and third doped regions and a second varactor terminal is coupled to the first doped region. At the interfaces of the doped regions are first and second depletion regions, the widths of which can be varied by varying the voltage across the terminals from zero to full reverse bias. At zero bias condition, junction capacitance (Cmax) is enhanced due to summation of two junction capacitances in parallel. At reverse bias condition, with the merging of the two junction depletion widths, the capacitor areas are drastically reduced, thereby reducing Cmin significantly.Type: GrantFiled: June 21, 2010Date of Patent: May 31, 2011Assignee: Chartered Semiconductor Manufacturing, Ltd.Inventor: Manju Sarkar
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Patent number: 7944019Abstract: A voltage-controlled semiconductor inductor and method is provided. According to various embodiments, the voltage-controlled inductor includes a conductor configured with a number of inductive coils. The inductor also includes a semiconductor material having a contact with at least a portion of at least one of the coils. The semiconductor material is doped to form a diode with a first doped region of first conductivity type, a second doped region of second conductivity type, and a depletion region. A voltage across the diode changes lengths of the first doped region, the second doped region and the depletion region, and adjacent coils in contact with at least one of the doped regions are electrically shorted, thereby varying the inductance of the inductor. In various embodiments, the inductor is electrically connected to a resistor and a capacitor to provide a tunable RLC circuit. Other aspects and embodiments are provided herein.Type: GrantFiled: February 27, 2009Date of Patent: May 17, 2011Assignee: Micron Technology, Inc.Inventor: Krupakar M. Subramanian
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Patent number: 7821103Abstract: An improved varactor diode (40) is obtained by providing a substrate (41) having a first surface (43), in which are formed a P+ region (53, 46) proximate the first surface (43), a first N region (54, 45) located beneath the P+ region (53, 46), an N well region (56, 44) located beneath the first N region (54, 45) and a first P counter-doped region (55) located between the first N region (54, 45) and the N well region (56, 44), thereby forming an P+NPN structure for the varactor diode. In some embodiments, a second P-type counter-doped region (59) is provided within the N-well region (56, 44) so as to reduce the N doping concentration within the N well region (56, 44) but without creating a further PN junction therein. The net doping profile (52) provides varactor diodes (40) having a larger tuning ratio than varactors (20) without such counter-doped regions. By interchanging N and P regions an N+PNP varactor is obtained.Type: GrantFiled: September 9, 2008Date of Patent: October 26, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Chun-Li Liu, Olin K. Hartin, Jay P. John, Vishal P. Trivedi, James A. Kirchgessner
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Patent number: 7781821Abstract: Provided is a parallel-varactor capacitor. The capacitor comprises a first varactor and a second varactor. The first varactor has a first capacitance which varies depending on voltages applied to a first anode and a first cathode. The second varactor has a second capacitance which varies depending on voltages applied to a second anode and a second cathode. The first anode is connected to the second cathode and the first cathode is connected to the second anode.Type: GrantFiled: July 19, 2007Date of Patent: August 24, 2010Assignee: Integrant Technologies Inc.Inventor: Seyeob Kim
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Patent number: 7741187Abstract: Large tuning range junction varactor includes first and second junction capacitors coupled in parallel between first and second varactor terminals. First and second plates of the capacitors are formed by three alternating doped regions in a substrate. The second and third doped regions are of the same type sandwiching the first doped region of the second type. A first varactor terminal is coupled to the second and third doped regions and a second varactor terminal is coupled to the first doped region. At the interfaces of the doped regions are first and second depletion regions, the widths of which can be varied by varying the voltage across the terminals from zero to full reverse bias. At zero bias condition, junction capacitance (Cmax) is enhanced due to summation of two junction capacitances in parallel. At reverse bias condition, with the merging of the two junction depletion widths, the capacitor areas are drastically reduced, thereby reducing Cmin significantly.Type: GrantFiled: September 20, 2007Date of Patent: June 22, 2010Assignee: Chartered Semiconductor Manufacturing, Ltd.Inventor: Manju Sarkar
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Patent number: 7705428Abstract: A varactor on a substrate is provided. The varactor comprises a bottom electrode, an upper electrode, a first dielectric layer and a conductive layer. The bottom electrode has several doped regions arranged in the substrate as an array with several rows and several columns, wherein the doped regions in adjacent columns are arranged alternatively. The upper electrode is located over the substrate and the upper electrode is composed of several electrode locations and has several openings, wherein each opening exposes the corresponding doped region. Furthermore, each electrode location is surrounded by three doped regions. The first dielectric layer is located between the substrate and the upper electrode. The conductive layer is located over the upper electrode, wherein the conductive layer and the upper electrode are isolated from each other and the conductive layer and the doped regions are electrically connected to each other.Type: GrantFiled: March 21, 2006Date of Patent: April 27, 2010Assignee: United Microelectronics Corp.Inventors: Cheng-Chou Hung, Hua-Chou Tseng
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Patent number: 7704845Abstract: Disclosed is a varactor and/or variable capacitor. The varactor/variable capacitor includes a plurality of first conductive-type wells vertically formed on a substrate, a plurality of second conductive-type ion implantation areas formed in the first conductive-type wells, at least one second conductive-type plug electrically connected to the second conductive-type ion implantation areas, an isolation layer formed at sides of an uppermost second conductive-type ion implantation area, and a first conductive-type ion implantation area in an uppermost first conductive-type well electrically disconnected from the uppermost second conductive-type ion implantation area by the isolation area.Type: GrantFiled: December 13, 2007Date of Patent: April 27, 2010Assignee: Dongbu HiTek Co., Ltd.Inventor: Su Lim
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Publication number: 20100096678Abstract: Varactor shunt switches based on a nonlinear dielectric tunability of BaxSr(1?x)TiO3 (BST) thin-film on a sapphire substrates are presented. Nanostructured BST thin-films with dielectric tunability as high as 4.3:1 can be obtained on sapphire substrates, with very low loss-tangents below 0.025 at zero-bias and 20 GHz. The large capacitance of the varactor at zero bias can shunt the input signal to ground isolating the output port, resulting in the OFF state. When applying a bias voltage of approximately 10 V (a dc electric field of ˜250 kV/cm), the varactor's capacitance can be reduced to a minimum, allowing maximum transmission to the output resulting in the ON state. The microwave switching performance of the varactor shunt switch can be compared with the RF MEMS switches for potential applications at microwave and millimeterwave frequencies.Type: ApplicationFiled: October 20, 2008Publication date: April 22, 2010Applicant: University of DaytonInventor: Guru Subramanyam
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Patent number: 7696604Abstract: Methods and heterostructure barrier varactor (HBV) diodes optimized for application with frequency multipliers at providing outputs at submillimeter wave frequencies and above. The HBV diodes include a silicon-containing substrate, an electrode over the silicon-containing substrate, and one or more heterojunction quantum wells of alternating layers of Si and SiGe of one or more electrodes of the diode. Each SiGe quantum well preferably has a floating SiGe layer between adjacent SiGe gradients followed by adjacent Si layers, such that, a single homogeneous structure is provided characterized by having no distinct separations. The plurality of Si/SiGe heterojunction quantum wells may be symmetric or asymmetric.Type: GrantFiled: October 23, 2007Date of Patent: April 13, 2010Assignee: International Business Machines CorporationInventors: Erik M. Dahlstrom, Alvin J. Joseph, Robert M. Rassel, David C. Sheridan
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Patent number: 7682919Abstract: A method in the fabrication of an integrated circuit including a PMOS varactor and an npn transistor, comprises the steps of (i) simultaneously forming buried n+-doped regions (31) for the PMOS varactor and the npn transistor in a p-doped substrate (10, 41); (ii) simultaneously forming n-doped wells (41) above the buried n+-doped regions (31); (iii) simultaneously forming field isolation areas (81) around the n-doped regions (41); (iv) forming a PMOS gate region (111, 194) and a p-doped base each in a respective one of the n-doped wells (41); and (v) simultaneously forming n+-doped contacts to the buried n+-doped regions (31); the contacts being separated from the n-doped wells (41). Source and drain regions may be formed in the PMOS n-well (inversion mode) or the PMOS n+-doped contact may be formed in the PMOS n-well instead of being separated from there (accumulation mode).Type: GrantFiled: April 22, 2004Date of Patent: March 23, 2010Assignee: Infineon Technologies AGInventor: Ted Johansson
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Patent number: 7683390Abstract: A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.Type: GrantFiled: February 25, 2008Date of Patent: March 23, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Tachibana, Chie Hongo, Hajime Nago, Shinya Nunoue
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Publication number: 20100059859Abstract: An improved varactor diode (40) is obtained by providing a substrate (70) having a first surface (73) and in which are formed a first N region (46) having a first peak dopant concentration (47) located at a first depth (48) beneath the surface (73), and a first P region having a second peak dopant concentration (50) greater than the first peak dopant concentration located at a second depth (51) beneath the surface less than the first depth (48), and a second P region (42) having a third peak dopant concentration (43) greater than the second peak dopant concentration and located at a third depth at or beneath the surface (73) less than the second depth (51), so that the first P region (49) provides a retrograde doping profile whose impurity concentration increases with distance from the inward edge (44) of the second P region (42) up to the second peak dopant concentration (50).Type: ApplicationFiled: September 9, 2008Publication date: March 11, 2010Applicant: FREESCALE SEMICONDUCTOR, INC.Inventor: Vishal P. Trivedi
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Patent number: 7579642Abstract: A semiconductor junction varactor utilizes gate enhancement for enabling the varactor to achieve a high ratio of maximum capacitance to minimum capacitance.Type: GrantFiled: April 18, 2006Date of Patent: August 25, 2009Assignee: National Semiconductor CorporationInventor: Constantin Bulucea
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Patent number: 7545007Abstract: A MOS varactor is formed having a gate electrode comprising at least two abutting oppositely doped regions shorted together, in which the two regions are implanted simultaneously with source/drain implants for first and second types of transistor; at least one contact to a lower electrode is also formed simultaneously with the source/drain implants for the first type of transistor; the varactor insulator is formed simultaneously with the gate insulator for one type of transistor; and the lower electrode is formed simultaneously with a well for the first type of transistor, so that no additional mask is required.Type: GrantFiled: August 8, 2005Date of Patent: June 9, 2009Assignee: International Business Machines CorporationInventors: Heidi L. Greer, Seong-Dong Kim, Robert M. Rassel, Kunal Vaed
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Patent number: 7511356Abstract: A voltage-controlled semiconductor inductor and method is provided. According to various embodiments, the voltage-controlled inductor includes a conductor configured with a number of inductive coils. The inductor also includes a semiconductor material having a contact with at least a portion of at least one of the coils. The semiconductor material is doped to form a diode with a first doped region of first conductivity type, a second doped region of second conductivity type, and a depletion region. A voltage across the diode changes lengths of the first doped region, the second doped region and the depletion region, and adjacent coils in contact with at least one of the doped regions are electrically shorted, thereby varying the inductance of the inductor. In various embodiments, the inductor is electrically connected to a resistor and a capacitor to provide a tunable RLC circuit. Other aspects and embodiments are provided herein.Type: GrantFiled: August 31, 2005Date of Patent: March 31, 2009Assignee: Micron Technology, Inc.Inventor: Krupakar M. Subramanian
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Patent number: 7378327Abstract: A junction varactor includes a gate finger lying across an ion well of a semiconductor substrate; a gate dielectric situated between the gate finger and the ion well; a first ion diffusion region with first conductivity type located in the ion well at one side of the gate finger, the first ion diffusion region serving as an anode of the junction varactor; and a second ion diffusion region with a second conductivity type located in the ion well at the other side of the gate finger, the second ion diffusion region serving as a cathode of the junction varactor. In operation, the gate of the junction varactor is biased to a gate voltage VG that is not equal to 0 volt.Type: GrantFiled: June 10, 2007Date of Patent: May 27, 2008Assignee: United Microelectronics Corp.Inventor: Ching-Hung Kao
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Publication number: 20080081426Abstract: A semiconductor device with having a MOS varactor and methods of fabricating the same are disclosed. The MOS varactor includes a metal gate electrode, an active semiconductor plate interposed between the metal gate electrode and the semiconductor substrate, and a capacitor dielectric layer interposed between the metal gate electrode and the active semiconductor plate. Further, a lower insulating layer insulates the MOS varactor from the semiconductor substrate. According to the present invention, a metal gate electrode is used to reduce poly depletion, thereby increasing a tuning range of the varactor, and to manufacture a reliable metal resistor without the need of an additional photomask.Type: ApplicationFiled: November 16, 2007Publication date: April 3, 2008Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Dae-Hyun Kim, Han-Su OH
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Publication number: 20070176217Abstract: A ferroelectric varactor suitable for capacitive shunt switching is disclosed. High resistivity silicon with a SiO2 layer and a patterned metallic layer deposited on top is used as the substrate. A ferroelectric thin-film layer deposited on the substrate is used for the implementation of the varactor. A top metal electrode is deposited on the ferroelectric thin-film layer forming a CPW transmission line. By using the capacitance formed by the large area ground conductors in the top metal electrode and bottom metallic layer, a series connection of the ferroelectric varactor with the large capacitor defined by the ground conductors is created. The large capacitor acts as a short to ground, eliminating the need for vias. The concept of switching ON and OFF state is based on the dielectric tunability of the ferroelectric thin-films. At 0 V, the varactor has the highest capacitance value, resulting in the signal to be shunted to ground, thus isolating the output from the input.Type: ApplicationFiled: October 15, 2004Publication date: August 2, 2007Applicant: UNIVERSITY OF DAYTONInventors: Guru Subramanyam, Andrei Vorobiev, Spartak Gevorgian
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Patent number: 7211493Abstract: A variable capacitor comprising a substrate having a first type ion-doped buried layer, a first type ion-doped well, a second type ion-doped region and a conductive layer thereon. The first type ion-doped well is formed within the substrate. The first type ion-doped well has a cavity. The first type ion-doped buried layer is in the substrate underneath the first type ion-doped well. The first type ion-doped buried layer and the first type ion-doped well are connected. The second type ion-doped region is at the bottom of the cavity of the first type ion-doped well. The conductive layer is above and in connection with the first type ion-doped buried layer.Type: GrantFiled: July 29, 2003Date of Patent: May 1, 2007Assignee: United Microelectronics Corp.Inventors: Jin-Horng Gau, Anchor Chen
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Publication number: 20060267150Abstract: A varactor is configured with first and second conducting layers, spaced apart from one another such that a given voltage can be applied across the first and second conducting layers. Further, an insulator arrangement includes at least one insulator layer disposed between the first and second conducting layers, configured to cooperate with the first and second conducting layers to produce a charge pool which changes responsive to changes in the given voltage such that a device capacitance value between the first and second conducting layers changes responsive to the given voltage. The insulator arrangement can include one layer, two distinct layers or more than two distinct layers. One or more of the layers can be an amorphous material. A zero-bias voltage version of the varactor is also described.Type: ApplicationFiled: July 7, 2005Publication date: November 30, 2006Inventor: Michael Estes