Advanced Micro Devices Corporation

Janet S Y Wang

Narbeh Derhacobian

Sameer S Haddad

Darlene G Hamilton

Ravi S Sunkavalli

Daniel Sobek

Chi K Chang

Michael Van Buskirk

Kulachet Tanpairoj

Tim Thurgate

Michael K Han

Narbeth Derhacobian

Daniel Sobeck

A method of programming that includes programming a fresh memory cell with a substrate that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. Baking the programmed fresh cell causing a charge loss in the channel while the remaining charge within the channel is distributed more locally at the first region when compared to the distribution of charge prior to the baking.

Method of programming a non-volatile memory cell using a baking process

A method and system for programming of the normal bits of a memory array of dual bit memory cells is accomplished by programming at a substantially high delta VT. The substantially higher VT assures that the memory array will maintain programmed data and erase data consistently after higher temperature stresses and/or customer operation over substantial periods of time. Furthermore, by utilizing substantially high gate and drain voltages during programming, programming times are kept short without degrading charge loss. A methodology is provided that determines the charge loss for single bit operation during program and erase cycles. The charge losses over cycling and stress are then utilized to determine an appropriate delta VT to be programmed into a command logic and state machine.

Higher program VT and faster programming rates based on improved erase methods

A system and methodology is provided for programming first and second bits of a memory array of dual bit memory cells at a substantially high delta VT. The substantially higher VT assures that the memory array will maintain programmed data and erase data consistently after higher temperature stresses and/or customer operation over substantial periods of time. At a substantially higher delta VT, programming of the first bit of the memory cell causes the second bit to program harder and faster due to the shorter channel length. Therefore, the present invention employs selected gate and drain voltages and programming pulse widths during programming of the first and second bit that assures a controlled first bit VT and slows down programming of the second bit. Furthermore, the selected programming parameters keep the programming times short without degrading charge loss.

Charge injection

A method of erasing a memory cell with a substrate that has a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains an initial amount of charge. The method includes applying a constant first voltage across the gate and applying a second constant voltage across said the region. A third constant voltage is applied in a region of the substrate outside of the first and second regions so that a first portion of the first amount of charge is removed from the charge trapping region.

Method of erasing a non-volatile memory cell using a substrate bias

A method of programming a memory cell with a substrate that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. The method includes applying a constant first voltage across the gate and applying a second constant voltage across the first region so as to generate a first charge injection region. The application of the second constant voltage is discontinued while simultaneously applying a third constant voltage across the first region so that a second charge injection region is generated that is larger than the first charge injection region.

Method of programming a non-volatile memory cell using a drain bias

A method of programming a memory cell with a substrate that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. The method includes applying a constant first voltage across the gate, applying a second constant voltage across the first region, and applying a third constant voltage across the second region that is near the avalanche breakdown voltage of the second region so that spillover electrons are significantly reduced in number within the channel when compared to if the third constant voltage is well below the avalanche breakdown voltage.

Method of drain avalanche programming of a non-volatile memory cell

A method of erasing a memory cell that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. The method includes: applying a voltage across the gate and the first region in accordance with a coarse erase sequence of voltages so that a portion of the first amount of charge is removed from the charge trapping region; and applying a voltage across the gate and the first region in accordance with a fine erase sequence of voltages so that a portion of the first amount of charge is removed from the charge trapping region.

Intelligent ramped gate and ramped drain erasure for non-volatile memory cells

A method of erasing a memory cell that includes a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains a first amount of charge. The method includes simultaneously applying a first positive voltage across the gate and a second positive voltage to the first region, wherein the second positive voltage is greater than the first positive voltage.

Positive gate erasure for non-volatile memory cells

A memory cell that includes a substrate that has a first region and a second region with a channel therebetween, wherein the first region generates hot carriers. The memory cell further includes a gate above the channel and a charge trapping region that contains a first amount of charge. A current limiter that limits the number of the generated hot carriers that can flow into the channel, wherein the current limiter does not control the voltage of the second region.

Method of programming a non-volatile memory cell using a current limiter

A method of erasing a memory cell that has a first region and a second region with a channel therebetween and a gate above the channel, and a charge trapping region that contains an initial amount of charge. The method includes applying a first voltage across the gate and the first region so that a first portion of the initial amount of charge is removed from the charge trapping region. Next, a second voltage is applied across the gate and the first region so that a second portion of the initial amount of charge is removed from the charge trapping region, wherein the second voltage is different than the first voltage.

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San Francisco, CA, United States of America

Janet S Y Wang