Patents Represented by Attorney Raymond Kam-On Kwong
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Patent number: 5705080Abstract: A process for removing deposits from within a space at least partially delimited by a surface which is subject to attack from a plasma includes the steps of placing on the surface a cover comprising a material which is inert to the plasma, and then removing the deposits.Type: GrantFiled: July 6, 1994Date of Patent: January 6, 1998Assignee: Applied Materials, Inc.Inventors: Cissy S. Leung, Lawrence Chung-Lai Lei, Sasson Somekh
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Patent number: 5671117Abstract: An electrostatic chuck for securing a semiconductor wafer on a pedestal having multiple apertures for the introduction of cooling gas beneath the wafer. The multiple apertures reduce overheating near the wafer edge and provide lower temperature gradients across the wafer. The wafer is held by electrostatic force against a laminate of an electrode layer sandwiched between two dielectric layers in such a way that the laminate presents a planar surface to the wafer for a substantial distance beyond the outer edge of the electrode layer. The laminate construction ensures that a large wafer area beyond the outer edge of the electrode is in contact with the laminate, to minimize cooling gas leakage near the edge, and provides a longer useful life by increasing the path length of dielectric material between the electrode layer and potentially damaging plasma material surrounding the chuck.Type: GrantFiled: March 27, 1996Date of Patent: September 23, 1997Assignee: Applied Materials Inc.Inventors: Semyon Sherstinsky, Shamouil Shamouilian, Manoocher Birang, Alfred Mak, Simon W. Tam
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Patent number: 5561620Abstract: A flash EEPROM cell array is erased by applying a relatively high positive voltage to the source region of the cell and a ground potential to the control gate of the cell while allowing the voltage of the drain region and the substrate region of the cell to float. By floating the substrate, the source current during erase is greatly reduced since the only DC current path is between the control gate and the source region. Since the source current is small, a double-diffused junction is not required so that the cell can occupy a minimum area for a given design rule and the cell fabrication process is simplified. In addition, the generation of high energy holes is suppressed and improved performance may be obtained. Because the source current is small during the erase operation, the high positive voltage at the source region can be generated by an on chip charge pump from a supply voltage as low as +3 V. This simplifies the design of memory boards on which many flash EEPROM chips are to be placed.Type: GrantFiled: July 31, 1995Date of Patent: October 1, 1996Assignee: Advanced Micro Devices, Inc.Inventors: Jian Chen, Nader Radjy
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Patent number: 5530803Abstract: A method for programming an integrated memory circuit and an integrated memory circuit structure for storing information are disclosed. The method of programming includes the steps of providing a program mode for programming the memory cells in accordance with total number of memory cells that is required to be programmed; and programming the memory cells in accordance with the program mode. The integrated memory circuit includes a program mode determining circuit, and a programming circuit operatively coupled to the program mode determining circuit for programming each of a plurality of block of memory cells according to its respective program mode.Type: GrantFiled: April 14, 1994Date of Patent: June 25, 1996Assignee: Advanced Micro Devices, Inc.Inventors: George Chang, Pearl Cheng
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Patent number: 5469097Abstract: A translator circuit for providing symmetrical switching delays for use with a power line for a differential amplifier having a first signal line and a complementary second signal line, the translator circuit including: a first voltage clamp coupled to the first signal line and to the power line for limiting a voltage differential between the power line and the first signal line; and a second voltage clamp coupled to the power line and the second signal line for limiting a voltage differential between the power line and the second signal line. The translator circuit provides reduced sensitivity to variations in process parameters, power supply voltages, temperature and manufacturing tolerances. The translator circuit also provides symmetrical tracking between the rise to rise and the fall to fall delays of an emitter coupled logic to complementary metal-oxide semiconductor translator circuit.Type: GrantFiled: May 10, 1995Date of Patent: November 21, 1995Assignee: Advanced Micro Devices, Inc.Inventor: Kenneth Ho
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Patent number: 5456756Abstract: A holding apparatus, a metal deposition system and a wafer processing method which preserve topographical marks, including those used as alignment targets, on a semiconductor wafer by preventing metal from depositing on such marks during metal deposition. The invention eliminates the need to use window mask and etch techniques to provide replication of topographical marks on a newly formed metal layer when a CMP planarization technique is used prior to metal deposition. As a result, cost, cycle time and yield loss due to the additional window mask and etch steps can be eliminated. The holding apparatus includes a wafer retainer for retaining a wafer which has at least one topographical mark and a clamp ring with at least one tab. The wafer is pressed against the clamp ring by the retainer for securing the wafer in the retainer.Type: GrantFiled: September 2, 1994Date of Patent: October 10, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Seshadri Ramaswami, Darin A. Chan
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Patent number: 5442304Abstract: A gate clamping circuit is disclosed that includes a logic gate and a bias circuit arrangement. Through this clamping circuit the speed of operation of the circuit during both low to high and high-to-low transitions of the output signal are optimized while power consumption is minimized.Type: GrantFiled: October 15, 1993Date of Patent: August 15, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Jack T. Wong, Fabiano Fontana, Martha Chan
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Patent number: 5438278Abstract: An output buffer circuit is disclosed that minimizes propagation delay and crowbar current. This circuit receives a data input signal and provides an output signal. This circuit includes a pull-up transistor, a first pull-down transistor, a speed improvement circuit and a crowbar current reduction circuit. The speed improvement circuit comprises an inverter with small propagation delay coupled to a second pull-down transistor which is smaller than the first pull-down transistor. The speed improvement circuit minimizes the propagation delay of the circuit when the data input signals changes from a high logic level to a low logic level by speeding up the initial rate of fall of the output signal due to the fast turning on of the second small pull-down transistor which receives the data input signal quickly through the small-propagation-delay inverter. The crowbar current reduction circuit comprises a first crowbar current reduction transistor which is smaller than the pull-up transistor.Type: GrantFiled: September 28, 1993Date of Patent: August 1, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Jack T. Wong, Fabiano Fontana, Henry Law
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Patent number: 5432463Abstract: A high speed multiple input NOR gate. In an illustrative embodiment, the invention includes a plurality of pull-down transistors for providing an output signal. A pull-up transistor is coupled to the plurality of pull-down transistors for providing a drive current. A regulator is coupled to the pull-up transistor for regulating the drive current in response to temperature and power supply voltage variation so as to maintain the speed of the output signal during a low-to-high transition of the output signal. In specific implementations, the NOR gate is designed to regulate the output signal so that a high level or a low level thereof is maintained at a predetermined level.Type: GrantFiled: October 15, 1993Date of Patent: July 11, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Jack T. Wong, Fabiano Fontana, Henry Law
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Patent number: 5424653Abstract: An output buffer circuit is provided which significantly reduces ground/Vcc bounce and glitches of signals provided to an integrated circuit. The circuit includes a plurality of transistors for providing a drive potential at the output of the device. The transistors are coupled such that they increase in size from the input to the output of the output buffer circuit. A control circuit provides control signals for sequentially turning off the transistors from the largest to smallest device thereby substantially reducing the Vcc bounce and glitches of the signals provided to the integrated circuit by the output buffer circuit.Type: GrantFiled: October 6, 1993Date of Patent: June 13, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Alan C. Folmsbee, Kyoung Kim
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Patent number: 5418482Abstract: A sense amplifier is provided that has improved speed from input to output, particularly during low-to-high transitions on the output and minimizes power consumption. By removing the product term window circuit from the critical node, the overall speed of the amplifier is maximized. In addition, circuitry is included to speed up low-to-high transitions, high-to-low transitions and provide increased noise immunity over temperature variations.Type: GrantFiled: October 15, 1993Date of Patent: May 23, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Jack T. Wong, Fabiano Fontana, Martha Chan
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Patent number: 5402081Abstract: An input buffer circuit is provided that has improved speed performance. The input buffer circuit has a voltage swing of V.sub.DD -V.sub.th to V.sub.SS. In so doing, the speed of the input buffer signal from input to output is significantly increased. In addition, the circuit also incorporates an additional current leaker transistor that limits the output high voltage from going above V.sub.DD -V.sub.th.Type: GrantFiled: October 12, 1993Date of Patent: March 28, 1995Assignee: Advanced Micro Devices, Inc.Inventors: Jack T. Wong, Fabiano Fontana, Susan Nguyen
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Patent number: 5386151Abstract: A low voltage charge pump operable with a low voltage power supply and a clock signal is provided for delivering a final output voltage which is higher than the supply voltage. The low voltage charge pump comprises MOS capacitors formed of MOS devices, each capacitor including a p-well acting as a plate of the respective capacitor. Through this arrangement, the effective area of the capacitor is increased resulting in an increase in capacitance. Therefore, a more efficient charge pumping effect is provided in a low voltage power supply such as 3.3 volts. The p-well of each of the capacitor is driven from ground voltage to one threshold voltage less than the supply voltage to minimize forward bias of the p-wells and the n-type substrates of the MOS devices.Type: GrantFiled: August 11, 1993Date of Patent: January 31, 1995Assignee: Advanced Micro Devices, Inc.Inventor: Alan C. Folmsbee