Ememory Technology Inc.

Ying-Je Chen

Wein-Town Sun

Wei-Ming Ku

Wei-Ren Chen

Cheng-Jye Liu

Chia-Fu Chang

Te-Hsun Hsu

Yu-Hsiung Tsai

Chun-Hsiao Li

Hsueh-Wei Chen

Yun-Jen Ting

Hong-Yi Liao

Mu-Ying Tsao

Shang-Wei Fang

Kai-Yuan Hsiao

Hsuen-Wei Chen

A memory cell of a non-volatile memory includes a memory element. The memory element is a transistor. The memory element includes an asymmetric spacer. In the memory element, a channel under the wider part of the spacer is longer. When the program operation of the memory element is performed, more carriers are injected into a charge-trapping layer of the spacer through the longer channel. Consequently, the program operation of the memory element is performed more efficiently, and the time period of performing the program operation is reduced.

Memory cell of non-volatile memory

A non-volatile memory includes a cell array, a current supply circuit, a path selecting circuit, a verification circuit and a control circuit. During a sample period of a verification action, the control circuit controls the current supply circuit to provide n M-th reference currents to the verification circuit and convert the n M-th reference currents into n reference voltages. During a verification period of the verification action, the control circuit controls n multi-level memory cells of a selected row of the cell array to generate n cell currents to the verification circuit and convert the n cell currents into n sensed voltages. The n verification devices generate the n verification signals according to the reference voltages and the sensed voltages. Accordingly, the control circuit judges whether the n multi-level memory cells have reached an M-th storage state.

Non-volatile memory with multi-level cell array and associated program control method

A programming and verifying method for a multi-level memory cell array includes following steps. In a step (a1), a first row of the multi-level memory cell array is set as a selected row, and A is set as 1. In a step (a2), memory cells in the selected row excluding the memory cells in the target storage state and bad memory cells are programmed to the A-th storage state. In a step (a3), if A is not equal to X, 1 is added to X and the step (a2) is performed again. In a step (a4), if A is equal to X, the program cycle is ended. In the step (a2), the first-portion memory cells of the selected row are subjected to plural write actions and plural verification actions until all of the first-portion memory cells reach the A-th storage state.

Programming and verifying method for multilevel memory cell array

A random bit cell includes a selection transistor, a first P-type transistor, and a second P-type transistor. The selection transistor has a first terminal coupled to a source line, a second terminal coupled to a common node, and a control terminal coupled to a word line. The first P-type transistor has a first terminal coupled to the common node, a second terminal coupled to a first bit line, and a floating gate. The second P-type transistor has a first terminal coupled to the common node, a second terminal coupled to a second bit line, and a floating gate. During an enroll operation, one of the first P-type transistor and the second P-type transistor is programmed by channel hot electron injection.

Random bit cell using P-type transistors

A random code generator includes a memory cell, two write buffers and two sensing circuits. The memory cell includes a first program path between a first source line and a first bit line, a second program path between the first source line and a second bit line, a first read path between a second source line and a third bit line, and a second read path between a third source line and a fourth bit line. The two write buffers are connected with the first bit line and the second bit line, respectively. The two sensing circuits are connected with the third bit line and the fourth bit line, respectively. The two sensing circuits generate a first output signal and the second output signal to the corresponding write buffers according to the read currents in the corresponding read paths.

Random code generator with floating gate transistor type memory cell

A nonvolatile memory structure includes a first PMOS transistor and a first floating-gate transistor on a first active region in a substrate, a second PMOS transistor and a second floating-gate transistor on a second active region in the substrate, and an n-type erase region in the substrate. A source line connects with sources of the first and the second PMOS transistors. A bit line connects with drains of the first and the second floating-gate transistors. A word line connects with first and the second select gates in the first and the second PMOS transistors respectively. An erase line connects with the n-type erase region. The first floating-gate transistor includes a first floating gate with an extended portion extending on a first portion of the n-type erase region. The second floating-gate transistor includes a second floating gate with an extended portion extending on a second portion of the n-type erase region.

Nonvolatile memory structure

A single-poly nonvolatile memory cell includes an SOI substrate having a semiconductor layer, a first OD region and a second OD region on the semiconductor layer, an isolation region separating the first OD region from the second OD region, a PMOS select transistor disposed on the first OD region, and a PMOS floating gate transistor disposed on the first OD region. The PMOS floating gate transistor is serially connected to the PMOS select transistor. The PMOS floating gate transistor comprises a floating gate overlying the first OD region. A floating gate extension is continuously extended from the floating gate to the second OD region and is capacitively coupled to the second OD region.

Single-poly nonvolatile memory cell structure having an erase device

A nonvolatile memory structure included a P substrate, an N well in the P substrate, and a PMOS storage transistor. The PMOS storage transistor includes a floating gate and an auxiliary gate disposed in close proximity to the floating gate. The floating gate and the auxiliary gate are disposed directly on the same floating gate channel of the PMOS storage transistor. A gap is provided between the auxiliary gate and the floating gate such that the auxiliary gate and the floating gate are separated from each other at least directly above the floating gate channel.

A method of programming a nonvolatile memory cell which comprises a select transistor and a memory transistor includes applying a preset limit current to a first input of the memory cell, applying a limit voltage to a current limiting circuit electrically connected to a second input of the memory cell, applying a limit voltage to stabilize a voltage drop of the memory cell, and applying a ramped gate voltage to the memory cell to program the memory cell with a preset limited current determined by the current limiting circuit.

Non-volatile memory device with program current clamp and related method

A nonvolatile memory device for reducing programming current and improving reliability comprises a memory cell array, a write circuit, and a verification circuit. The memory cell array comprises memory cells arranged at crossing points of a bit-line and word-line matrix of the memory cell array. The write circuit provides multiple variable pulses to each word-line for programming. The multiple variable pulses have predetermined amplitude for keeping gate injection current roughly maximum while lowering conduction current during programming operation. The verification circuit senses variation of the conduction current during the programming operation, and disables the programming operation if the sensed conduction current during the programming operation reaches a predetermined value.

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Taichung, Taiwan

Ying-Je Chen