Silicon Storage Technology, Inc.

Yuri Tkachev

Nhan Do

Alexander Kotov

Jinho Kim

Elizabeth Cuevas

Catherine Decobert

Parviz Ghazavi

Henry A Om'Mani

Bruno Villard

Gilles Festes

Bernard Bertello

Xian Liu

Amitay Levi

Steven Lemke

Chien-Sheng Su

Viktor Markov

Yaw Wen Hu

Mandana Tadayoni

Jong-Won Yoo

James Yingbo Jia

Jean Francois Thiery

Hieu Van Tran

Thuan Vu

Vipin Tiwari

Xiaozhou Qian

Kai Man Yue

Serguei Jourba

Ning Bai

Chien Sheng Su

Louisa Schneider

Fan Luo

Latt Tee

Cynthia Fung

Steven Malcolm Lemke

A method of testing non-volatile memory cells formed on a die includes erasing the memory cells and performing a first read operation to determine a lowest read current RCfor the memory cells and a first number Nof the memory cells having the lowest read current RC. A second read operation is performed to determine a second number Nof the memory cells having a read current not exceeding a target read current RC. The target read current RCis equal to the lowest read current RCplus a predetermined current value. The die is determined to be acceptable if the second number Nis determined to exceed the first number Nplus a predetermined number. The die is determined to be defective if the second number Nis determined not to exceed the first number Nplus the predetermined number.

Method of determining defective die containing non-volatile memory cells

Embodiments for ultra-precise tuning of a selected memory cell are disclosed. The selected memory cell optionally is first programmed using coarse programming and fine programming methods. The selected memory cell then undergoes ultra-precise programming through the programming of an adjacent memory cell. As the adjacent memory cell is programmed, capacitive coupling between the floating gate of the adjacent memory cell and the floating gate of the selected memory cell will cause the voltage of the floating gate of the selected memory cell to increase, but in smaller increments than could be achieved by programming the selected memory cell directly. In this manner, the selected memory cell can be programmed with ultra-precise gradations.

Ultra-precise tuning of analog neural memory cells in a deep learning artificial neural network

A memory device includes a semiconductor substrate with memory cell and logic regions. A floating gate is disposed over the memory cell region and has an upper surface terminating in opposing front and back edges and opposing first and second side edges. An oxide layer has a first portion extending along the logic region and a first thickness, a second portion extending along the memory cell region and has the first thickness, and a third portion extending along the front edge with the first thickness and extending along a tunnel region portion of the first side edge with a second thickness less than the first thickness. A control gate has a first portion disposed on the oxide layer second portion and a second portion vertically over the front edge and the tunnel region portion of the first side edge. A logic gate is disposed on the oxide layer first portion.

Method of forming split gate memory cells with thinned side edge tunnel oxide

A method of forming a memory device includes forming a floating gate on a memory cell area of a semiconductor substrate, having an upper surface terminating in an edge. An oxide layer is formed having first and second portions extending along the logic and memory cell regions of the substrate surface, respectively, and a third portion extending along the floating gate edge. A non-conformal layer is formed having a first, second and third portions covering the oxide layer first, second and third portions, respectively. An etch removes the non-conformal layer third portion, and thins but does not entirely remove the non-conformal layer first and second portions. An etch reduces the thickness of the oxide layer third portion. After removing the non-conformal layer first and second portions, a control gate is formed on the oxide layer second portion and a logic gate is formed on the oxide layer first portion.

Method of forming split gate memory cells with thinned tunnel oxide

A memory device with a memory cell and control circuitry. The memory cell includes source and drain regions formed in a semiconductor substrate, with a channel region extending there between. A floating gate is disposed over a first portion of the channel region for controlling its conductivity. A select gate is disposed over a second portion of the channel region for controlling its conductivity. A control gate is disposed over the floating gate. An erase gate is disposed over the source region and adjacent to the floating gate. The control circuitry is configured to perform a program operation by applying a negative voltage to the erase gate for causing electrons to tunnel from the erase gate to the floating gate, and perform an erase operation by applying a positive voltage to the erase gate for causing electrons to tunnel from the floating gate to the erase gate.

Method of programming a split-gate flash memory cell with erase gate

A system and method to inhibit the erasing of a portion of a sector of split gate flash memory cells while allowing the remainder of the sector to be erased is disclosed. The inhibiting is controlled by control logic that applies one or more bias voltages to the portion of the sector whose erasure is to be inhibited.

System and method to inhibit erasing of portion of sector of split gate flash memory cells

A memory device having a substrate of semiconductor material of a first conductivity type, first and second spaced-apart regions in the substrate of a second conductivity type, with a channel region in the substrate therebetween, a conductive floating gate over and insulated from the substrate, wherein the floating gate is disposed at least partially over the first region and a first portion of the channel region, a conductive second gate laterally adjacent to and insulated from the floating gate, wherein the second gate is disposed at least partially over and insulated from a second portion of the channel region, and wherein at least a portion of the channel region first portion is of the second conductivity type.

Split-gate memory cell with depletion-mode floating gate channel, and method of making same

A method of reading a memory device having rows and columns of memory cells formed on a substrate, where each memory cell includes spaced apart first and second regions with a channel region therebetween, a floating gate disposed over a first portion of the channel region, a select gate disposed over a second portion of the channel region, a control gate disposed over the floating gate, and an erase gate disposed over the first region. The method includes placing a small positive voltage on the unselected source lines, and/or a small negative voltage on the unselected word lines, during the read operation to suppress sub-threshold leakage and thereby improve read performance.

Low leakage, low threshold voltage, split-gate flash cell operation

A method of operating a memory cell that comprises first and second regions spaced apart in a substrate with a channel region therebetween, a floating gate disposed over the channel region and the fir region, a control gate disposed over the channel region and laterally adjacent to the floating gate with a portion disposed over the floating gate, and a coupling gate disposed over the first region and laterally adjacent to the floating gate. A method of erasing the memory cell includes applying a positive voltage to the control gate and a negative voltage to the coupling gate. A method of reading the memory cell includes applying positive voltages to the control gate, to the coupling gate, and to one of the first and second regions.

Method of operating a split gate flash memory cell with coupling gate

A non-volatile memory cell includes a substrate of a first conductivity type with first and second spaced apart regions of a second conductivity type, forming a channel region therebetween. A select gate is insulated from and disposed over a first portion of the channel region which is adjacent to the first region. A floating gate is insulated from and disposed over a second portion of the channel region which is adjacent the second region. Metal material is formed in contact with the floating gate. A control gate is insulated from and disposed over the floating gate. An erase gate includes a first portion insulated from and disposed over the second region and is insulated from and disposed laterally adjacent to the floating gate, and a second portion insulated from and laterally adjacent to the control gate and partially extends over and vertically overlaps the floating gate.

Split gate non-volatile flash memory cell having a silicon-metal floating gate and method of making same

A method of operating a memory cell that comprises first and second regions spaced apart in a substrate with a channel region therebetween, a floating gate disposed over the channel region and the first region, a control gate disposed over the channel region and laterally adjacent to the floating gate with a portion disposed over the floating gate, and a coupling gate disposed over the first region and laterally adjacent to the floating gate. A method of erasing the memory cell includes applying a positive voltage to the control gate and a negative voltage to the coupling gate. A method of reading the memory cell includes applying positive voltages to the control gate, to the coupling gate, and to one of the first and second regions.

An improved split gate non-volatile memory cell is made in a substantially single crystalline substrate of a first conductivity type, having a first region of a second conductivity type, a second region of the second conductivity type, with a channel region between the first region and the second region in the substrate. The cell has a select gate above a portion of the channel region, a floating gate over another portion of the channel region, a control gate above the floating gate and an erase gate adjacent to the floating gate. The erase gate has an overhang extending over the floating gate. The ratio of the dimension of the overhang to the dimension of the vertical separation between the floating gate and the erase gate is between approximately 1.0 and 2.5, which improves erase efficiency.

Split gate non-volatile flash memory cell having a floating gate, control gate, select gate and an erase gate with an overhang over the floating gate, array and method of manufacturing

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Sunnyvale, CA, United States of America

Yuri Tkachev