Patents by Inventor Ray Beffa
Ray Beffa 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: 7120073Abstract: The illustrated embodiments relate to a process for improving retention time of a set of integrated circuit devices. The process comprises placing the set of integrated circuit devices in a reverse bias condition, and elevating the surrounding temperature of the set of integrated circuit devices for a predetermined period of time.Type: GrantFiled: April 7, 2005Date of Patent: October 10, 2006Assignee: Micron Technology, Inc.Inventors: Russell L. Meyer, Ray Beffa
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Patent number: 7069484Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: GrantFiled: July 21, 2003Date of Patent: June 27, 2006Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Publication number: 20050174871Abstract: The illustrated embodiments relate to a process for improving retention time of a set of integrated circuit devices. The process comprises placing the set of integrated circuit devices in a reverse bias condition, and elevating the surrounding temperature of the set of integrated circuit devices for a predetermined period of time.Type: ApplicationFiled: April 7, 2005Publication date: August 11, 2005Inventors: Russell Meyer, Ray Beffa
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Patent number: 6898138Abstract: The illustrated embodiments relate to reducing variable retention time in dynamic random access memory (DRAM) integrated circuit devices. Memory cells that comprise the DRAM device are placed in a reverse bias condition. While under reverse bias, the DRAM device is maintained at an elevated temperature for a predetermined time.Type: GrantFiled: August 29, 2002Date of Patent: May 24, 2005Assignee: Micron Technology, Inc.Inventors: Russell L. Meyer, Ray Beffa
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Publication number: 20050091560Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: ApplicationFiled: July 21, 2003Publication date: April 28, 2005Inventor: Ray Beffa
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Publication number: 20040042306Abstract: The illustrated embodiments relate to reducing variable retention time in dynamic random access memory (DRAM) integrated circuit devices. Memory cells that comprise the DRAM device are placed in a reverse bias condition. While under reverse bias, the DRAM device is maintained at an elevated temperature for a predetermined time.Type: ApplicationFiled: August 29, 2002Publication date: March 4, 2004Inventors: Russell L. Meyer, Ray Beffa
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Patent number: 6625073Abstract: A semiconductor memory device includes a die having a semiconductor memory circuit formed thereon and a plurality of pads at the periphery of the die that are electrically coupled to the circuit. Electrically conductive leads have a pin end for external coupling, and a free end electrically connected by bond wires to certain pads on the die. An encapsulating material such as epoxy encapsulates the die, bond wires and free ends of the leads to form a packaged chip. A superfluous lead such as a redundant voltage supply lead or non-connected lead is coupled, by means of a bond wire, to a pad that, in turn, is coupled to a voltage boosting circuit on the die. The voltage boosting circuit is coupled to row lines in the semiconductor memory circuit to provide boosted voltage thereto. External power can thereby be provided to the row lines, through the voltage boosting circuits, to simultaneously enable at least half of the row lines during stress testing of the chip.Type: GrantFiled: November 12, 1996Date of Patent: September 23, 2003Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Patent number: 6622270Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: GrantFiled: December 13, 2001Date of Patent: September 16, 2003Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Patent number: 6442719Abstract: A method for identifying intercell defects in a memory device activates a plurality of spaced-apart rows simultaneously. Each of the rows includes cells that are written to logic states corresponding to high voltages. Cells in rows adjacent to the activated rows are written to logic states corresponding to low voltages. After the rows are activated, a testing interval passes to allow charge from cells of the activated rows to leak to adjacent cells through any stringers or other defects. In a device according to the invention, a variable voltage level circuit is incorporated in a precharge and equalization circuit to allow both inverting and non-inverting digit lines of the memory array to be set at the same voltage levels. Because the inverting and non-inverting digit lines are held at the same voltage levels, the number of word lines that can be activated for testing is increased, thereby reducing the overall time for testing.Type: GrantFiled: May 16, 2000Date of Patent: August 27, 2002Assignee: Micron Technology, Inc.Inventors: Ray Beffa, William K. Waller
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Publication number: 20020083384Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: ApplicationFiled: December 13, 2001Publication date: June 27, 2002Inventor: Ray Beffa
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Patent number: 6347386Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: GrantFiled: July 7, 2000Date of Patent: February 12, 2002Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Patent number: 6233185Abstract: A memory self-stress mode capable of use during wafer burn-in such as for dynamic random access memory (DRAM) integrated circuits. A burn-in power supply voltage and ground voltage delivered to a common node of a plurality of memory cell storage capacitors and to an equilibrate node coupled to bit lines. An all row high test cycles word lines between a binary low logic level and a binary high logic level, thereby stressing the dielectric of the memory cell storage capacitors by imposing stress voltages of differing polarity. A half row high test cycles alternate word lines of a word line sequence thereby stressing undesired short circuit connections between adjacent word lines.Type: GrantFiled: February 25, 1999Date of Patent: May 15, 2001Assignee: Micron Technology, Inc.Inventors: Ray Beffa, Leland R. Nevill, Warren M. Farnworth, Eugene H. Cloud, William K. Waller
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Patent number: 6181154Abstract: A semiconductor memory device includes a die having a semiconductor memory circuit formed thereon and a plurality of pads at the periphery of the die that are electrically coupled to the circuit. Electrically conductive leads have a pin end for external coupling, and a free end electrically connected by bond wires to certain pads on the die. An encapsulating material such as epoxy encapsulates the die, bond wires and free ends of the leads to form a packaged chip. A superfluous lead such as an address lead unused during testing, redundant voltage supply lead or non-connected lead is coupled, by means of a bond wire, to a pad that, in turn, is coupled through a switching transistor to a common cell plate or DVC2 node for all storage capacitors in the memory circuit. External power can thereby be provided to the DVC2 node to simultaneously apply a high voltage to this node of all capacitors during stress testing of the chip.Type: GrantFiled: January 26, 1999Date of Patent: January 30, 2001Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Patent number: 6128756Abstract: A method and apparatus for testing semiconductor memory chips, such as DRAMs, having a plurality of memory cells or bits. Each memory chip has a unique identifier stored in a database. Tests are performed on the memory chips and when a memory chip fails a test, the memory chip is placed in a repair bin and a test identifier is stored in the database in association with the memory chip identifier. In order to repair the memory chip, failed tests are read out of the database and such tests are again performed on the failed memory chip in order to determine which memory cell in the memory chip is faulty. The failed memory cells are then repaired.Type: GrantFiled: September 9, 1998Date of Patent: October 3, 2000Assignee: Micron Technology, Inc.Inventor: Ray Beffa
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Patent number: 6094734Abstract: A test arrangement for a memory device wherein the equilibration voltage DVC2 is adjusted up or down relative to a nominal value and coupled to one of the bitlines of the paired bitlines of the memory array, while the equilibrating circuit is held disabled, and then the sense amplifiers are used to pull the bitlines to logic 1 and logic 0 levels initializing the bitlines to test data. Appropriate word lines are fired to copy the test data to some or all of the other rows of the memory array, allowing memory tests to be conducted. In another embodiment, a fixed voltage is applied to one of the bitlines of individual bitlines pairs and the sense amplifiers are used to pull the paired bitlines to the correct voltage. In a further embodiment, fixed voltages Vcc and ground are applied to the bitlines of each bitline pair with the sense amplifier being held disabled. The test arrangement can be implemented as a self-test feature for the memory device.Type: GrantFiled: August 22, 1997Date of Patent: July 25, 2000Assignee: Micron Technology, Inc.Inventors: Ray Beffa, Eugene H. Cloud, Leland R. Nevill, Ken Waller, Warren M. Farnworth
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Patent number: 6079037Abstract: A method for identifying intercell defects in a memory device activates a plurality of spaced-apart rows simultaneously. Each of the rows includes cells that are written to logic states corresponding to high voltages. Cells in rows adjacent to the activated rows are written to logic states corresponding to low voltages. After the rows are activated, a testing interval passes to allow charge from cells of the activated rows to leak to adjacent cells through any stringers or other defects. In a device according to the invention, a variable voltage level circuit is incorporated in a precharge and equalization circuit to allow both inverting and non-inverting digit lines of the memory array to be set at the same voltage levels. Because the inverting and non-inverting digit lines are held at the same voltage levels, the number of word lines that can be activated for testing is increased, thereby reducing the overall time for testing.Type: GrantFiled: August 20, 1997Date of Patent: June 20, 2000Assignee: Micron Technology, Inc.Inventors: Ray Beffa, William K. Waller
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Patent number: 6058056Abstract: A test circuit detects defective memory cells in a memory device. The test circuit includes a test mode terminal adapted to receive a test mode signal. An error detection circuit includes a plurality of inputs and an output, each input coupled to some of the plurality of memory cells. The error detection circuit develops an active error signal on an output when the binary value of data on at least one input is different from predetermined binary values of data. A control circuit is coupled to the test mode terminal, the error detection circuit, and the memory cells. The control circuit is operable responsive to the test mode signal being active to apply the data of accessed memory cells to the associated inputs of the error detection circuit such that the error detection circuit drives the error signal active when the binary value of the data stored in at least one accessed memory cell is different from predetermined binary values.Type: GrantFiled: April 30, 1998Date of Patent: May 2, 2000Assignee: Micron Technology, Inc.Inventors: Ray Beffa, Leland R. Nevill, Neil L. Hansen, Eugene H. Cloud
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Patent number: 6003149Abstract: A method of testing a memory array is disclosed, the method comprising writing a test pattern to the memory array in as few as one or two RAS cycles by first activating the input/output data lines and then selectively activating multiple rows and columns. The method can be used with a variety of test environments. For example, the disclosed method may be implemented in testing using automated test equipment, and may also be incorporated in devices having built-in self-test circuitry. The disclosed method reduces the time required to test the memory array with minimal additional circuitry and no encroachment on valuable die real estate.Type: GrantFiled: August 22, 1997Date of Patent: December 14, 1999Assignee: Micron Technology, Inc.Inventors: Leland R. Nevill, Ray Beffa, Ken Waller, Eugene H. Cloud, Warren M. Farnworth
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Patent number: 5982682Abstract: A sense amplifier senses and stores data from a memory cell in an array of memory cells arranged in rows and columns. The sense amplifier includes a sense circuit having a pair of first and second complementary digit lines which senses a voltage differential between the first and second complementary digit lines and in response to the sensed voltage differential drives the first and second complementary digit lines to voltage levels corresponding to complementary logic states. An isolation circuit is coupled between the pair of first and second complementary digit lines of the sense amplifier and a pair of first and second complementary digit lines associated with a column of memory cells. The isolation circuit is operable to couple the first complementary digit line of the sense amplifier to the first complementary digit line of the column of memory cells and the second complementary digit line of the sense amplifier to the secondary complementary digit line of the column of memory cells.Type: GrantFiled: March 12, 1998Date of Patent: November 9, 1999Assignee: Micron Technology, Inc.Inventors: Leland R. Nevill, Ray Beffa, Warren M. Farnworth, Gene Cloud
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Patent number: RE38956Abstract: A test circuit detects defective memory cells in a memory device. The test circuit includes a test mode terminal adapted to receive a test mode signal. An error detection circuit includes a plurality of inputs and an output, each input coupled to some of the plurality of memory cells. The error detection circuit develops an active error signal on an output when the binary value of data on at least one input is different from predetermined binary values of data. A control circuit is coupled to the test mode terminal, the error detection circuit, and the memory cells. The control circuit is operable responsive to the test mode signal being active to apply the data of accessed memory cells to the associated inputs of the error detection circuit such that the error detection circuit drives the error signal active when the binary value of the data stored in at least one accessed memory cell is different from predetermined binary values.Type: GrantFiled: May 2, 2002Date of Patent: January 31, 2006Assignee: Micron Technology, Inc.Inventors: Ray Beffa, Leland R. Nevill, Neil L. Hansen, Eugene H. Cloud