National Semiconductor Corporation

Hengyang James Lin

Pavel Poplevine

Andrew J Franklin

Visvamohan Yegnashankaran

Ernes Ho

Annie-Li-Keow Lum

Umer Ahmed Khan

Kevin C Weaver

Annie-Li-Koow Lum

A non-volatile memory (NVM) cell comprises an NMOS control transistor having commonly-connected source, drain and bulk region electrodes and a gate electrode connected to a storage node; a PMOS erase transistor having commonly-connected source, drain and bulk region electrodes and a gate electrode connected to the storage node; an NMOS data transistor having source, drain and bulk region electrodes and a gate electrode connected to the storage node, the bulk region electrode being connected to a common bulk node; the first NMOS pass gate transistor having a source electrode connected to the drain electrode of the NMOS data transistor, a drain electrode, a bulk region electrode connected to the common bulk node, and a gate electrode; and a second NMOS pass gate transistor having a drain electrode connected to the source electrode of the NMOS data transistor, a source electrode, a bulk region electrode connected to the common bulk node, and a gate electrode.

5-transistor non-volatile memory cell

NPN and PNP bipolar junction transistors are formed on a wafer in a fabrication process that eliminates the heavily-doped buried layers and the lightly-doped epitaxial layer by forming back side collector contacts that are electrically connected to an interconnect structure on the top side of the wafer with through-the-wafer contacts.

Bipolar transistor and method of forming the bipolar transistor with a backside contact

In a SRAM structure, space and power saving is achieved by providing row and column select lines to select a specific bit cell, and reducing the number of bit lines in the structure used for writing to and reading from the bit cells. The number of bit lines is reduced by sharing bit lines of adjacent bit cells. Furthermore, in order to achieve power saving, the load on the row select lines is reduced by sharing the pass gates between adjacent bit cells that are used to control precharging, reading from and writing to the bit cells.

Bit line sharing and word line load reduction for low AC power SRAM architecture

A non-volatile memory (NVM) cell splits its basic functions, i.e. program, erase, read and control, among a four PMOS transistor structure, allowing independent optimization of each cell function. The cell structure also includes an embedded static random access memory (SRAM) cell that utilizes a latch structure to preprogram data to be written to the cell and a plurality of cascoded NMOS pass gates. The cell structure reduces total programming time and provides the flexibility of programming the entire cell array simultaneously or one row or sector of the array at a time.

Method of hot electron injection programming of a non-volatile memory (NVM) cell array in a single cycle

An integrated circuit test method is provided that utilizes shared tester resources physically located at different geographical sites throughout the world to test specific integrated circuits, thereby maximizing utilization of all tester resources and, thereby, dramatically reducing the overall cost to test.

World-wide distributed testing for integrated circuits

A non-volatile memory (NVM) cell splits its basic function, i.e. program, erase, read and control, among a four PMOS transistor structure, allowing independent optimization of each function. The cell structure also includes an embedded static random access memory (SRAM) cell that utilizes a latch structure to preprogram data to be written to the cell. The programming method for the cell utilizes a reverse Fowler-Nordheim tunneling mechanism with a very small programming current, allowing an entire NVM array to be programmed at one cycle.

Non-volatile memory cell with improved programming technique

In accordance with a method of programming an NVM array that includes 4-transistor PMOS non-volatile memory (NVM) cells having commonly connected floating gates, for all the cell's in the array that are to be programmed, all the electrodes of the cell are grounded. Then, an inhibiting voltage Vn is applied to the bulk-connected source region Vr of the cell's read transistor Pr, to the commonly connected drain, bulk and source regions Ve of the cell's erase transistor Pe, and to the drain region Dr of the read transistor Pr. The source region Vp and the drain region Dp of the cell's programming transistor Pw are grounded. The bulk Vnw of the programming transistor Pw is optional; it can be grounded or remain at the inhibiting voltage Vn. For all cells in the NVM array that are not selected for programming, the inhibiting voltage Vn is applied to Vr, Ve and Dr and is also applied to Vp, Dp and Vnw. The control gate voltage Vc of the cell's control transistor Pc is then swept from 0V to a maximum programming voltage Vcmax in a programming time Tprog. The control gate voltage Vc is then ramped down from the maximum programming voltage Vcmax to 0V. All electrodes of the cell and the inhibiting voltage Vn are then returned to ground.

Reverse fowler-nordheim tunneling programming for non-volatile memory cell

In a ROM structure, power consumption is reduced by providing for pre-discharging of only the bit line corresponding to the memory location that is being read. Column select lines are coupled to logic to switch in a pre-discharging circuit prior to reading, and to disconnect, from the pre-discharging circuit during reading, only the bit line corresponding to the memory location being read.

Low power ROM architecture

In a SRAM structure, power consumption is reduced by providing a structure which allows specific memory cells to be selected using word lines and column select lines, and reducing the load on the column address lines by dividing the load into sectors. The dividing into sectors is achieved by making use of sector select lines for selecting two or more rows of cells, and logically ANDing the sector select lines with the column select lines.

Low AC power SRAM architecture

A ROM array which provides for reduced size and power consumption. The bit cell of the ROM provides that a first type of information is stored in the bit cell when a transistor is disposed between a bit line and a word line, and a second type of information is stored in the cell when no transistor is disposed between the bit line and the word line. In the bit cell a contact between a bit line and a region where a transistor drain can be formed in a substrate is provided in those instances when a transistor is formed between the bit line and a word line. In those instances when a bit cell provides no transistors between the word line and the bit line, no contact is provided between the bit line and the region where a transistor drain can be formed. Further, where a bit cell does not provide a transistor between the bit line and the word line a bit cell region in the substrate can consist substantially of an isolating dielectric material.

High density ROM architecture

A ROM system which provides for reduced size and power consumption. This ROM systems allows for inverting the programming and sensing of information in bit cells of the ROM to reduce the number of transistors in bit cells of the ROM. Further bit cells of the ROM provide that a first type of information is stored in the bit cell when a transistor is disposed between a bit line and a word line, and a second type of information is stored in the cell when no transistor is disposed between the bit line and the word line. In the bit cell a contact between a bit line and a region where a transistor drain can be formed in a substrate is provided in those instances when a transistor is formed between the bit line and a word line. In those instances when a bit cell provides no transistors between the word line and the bit line, no contact is provided between the bit line and the region where a transistor drain can be formed.

High density ROM architecture with inversion of programming

A static RAM bit cell and a system and method for operating an array of such static RAM bit cells. The static RAM bit cell herein includes a cell of four transistors configured to store data. It also includes a pair of word line pass transistors and a pair of column pass transistors coupled to the cell of four transistors. The word line pass transistors are coupled to a word line such that they can be opened in closed in response to a signal on the word line. The column pass transistors are coupled to a column select transistor such that they can be opened and closed in response to a signal on the column select line. Using this configuration signals can be generated on the word line and the column select line so that only a small fraction of the total number of static RAM bit cells in an array need to be charged and discharged in connection with performing read and write operations to a specific static RAM bit cell.

Low power static RAM architecture

A low capacitance multilevel metal interconnect structure for use in integrated circuits that provides for increased IC device speed and that includes a plurality of patterned metal layers separated and supported by an interconnect dielectric material. The low capacitance multilevel metal interconnect structure has interconnect structure related capacitance lowering gaps in the interconnect dielectric material with the gaps, adjoining at least one of the patterned metal layers. While the gaps adjoin at least the uppermost patterned metal layer, they can also extend downward through the interconnect dielectric material such that they also adjoin one or more patterned metal layers that underlie the uppermost patterned metal layer. A process for the manufacture of the low capacitance multilevel metal interconnect structure includes a step of removing interconnect dielectric material from a conventional multilevel metal interconnect structure to form gaps adjoining at least one of the patterned metal layers. The gaps are formed without removing a substantial amount of interconnect dielectric material from directly underneath any patterned metal layer. This removal can be accomplished with an anisotropic etch and the gaps can be filled with air.

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San Ramon, CA, United States of America

Hengyang James Lin