Taiwan Semiconductor Manufacturing Comp. Ltd.

Nai-Chao Su

Wen-Ting Chu

Kuo-Chi Tu

Chu-Jie Huang

Sheng-Hung Shih

Chia-Ta Hsieh

Chen-Ming Huang

Po-Kai Hsu

Fu-Chen Chang

Josh Lin

Chi-Wei Ho

Shih-Jung Tu

Kao-Chao Lin

Shih-Ching Lee

Methods for programming memory cells of a resistive memory device include applying a voltage pulse sequence to a memory cell to set a logic state of the memory cell. An initial set sequence of voltage pulses may be applied to the memory cell, followed by a reform voltage pulse having an amplitude greater than the amplitudes of the initial set sequence, and within ±5% of the amplitude of a voltage pulse used in an initial forming process. Additional voltage pulses having amplitudes that are less than the amplitude of the reform voltage pulse may be subsequently applied. By applying a reform voltage pulse in the middle of, or at the end of, a memory set sequence including multiple voltage pulses, a resistive memory device may have a larger memory window and improved data retention relative to resistive memory devices programmed using conventional programming methods.

Methods for enlarging the memory window and improving data retention in resistive memory device

Methods for programming memory cells of a resistive memory device include applying a voltage pulse sequence to a memory cell to set a logic state of the memory cell. An initial set sequence of voltage pulses may be applied to the memory cell, followed by a reform voltage pulse having an amplitude greater than the amplitudes of the initial set sequence, and within &#xb1;5% of the amplitude of a voltage pulse used in an initial forming process. Additional voltage pulses having amplitudes that are less than the amplitude of the reform voltage pulse may be subsequently applied. By applying a reform voltage pulse in the middle of, or at the end of, a memory set sequence including multiple voltage pulses, a resistive memory device may have a larger memory window and improved data retention relative to resistive memory devices programmed using conventional programming methods.

Methods for enlarging the memory window and improving data retention in restistive memory device

A method of forming a memory device includes: forming a polish stop layer over a metallization layer in an inter-metal dielectric layer; performing an etching process to form an opening in the polish stop layer, in which a sidewall of the opening extends at an acute angle relative to a top surface of the polish stop layer; forming an electrode material in the opening and over the polish stop layer; planarizing the electrode material until a top surface of the polish stop layer is exposed so as to form a bottom electrode surrounded by the polish stop layer; and forming a stack of a resistance switching layer and a top electrode over the bottom electrode.

Method of forming memory device

A memory device includes a metal structure, a first dielectric layer, a bottom electrode, a second dielectric layer, a resistance switching layer, and a top electrode. The first dielectric layer surrounds the metal structure. The bottom electrode is in contact with a top surface of the metal structure. The second dielectric layer surrounds the bottom electrode, in which a top surface of the bottom electrode is higher than a top surface of the second dielectric layer. The resistance switching layer is over the bottom electrode. The top electrode is over the resistance switching layer.

Memory device and method for forming the same

A memory device includes a bottom electrode, a resistance switching layer and a top electrode. The bottom electrode is over a metallization layer embedded in an inter-metal dielectric layer. The bottom electrode has a top surface and a sidewall that extends at an obtuse angle relative to the top surface. The resistance switching layer is over the bottom electrode. The top electrode is over the resistance switching layer.

Memory device and fabrication thereof

A flash memory device is disposed on a semiconductor substrate. The flash memory device includes flash memory cells arranged in rows and columns. Respective flash memory cells include respective access transistors and respective floating gate transistors. The respective access transistors have respective access gates, and the respective floating gate transistors have respective control gates arranged over respective floating gates. First and second wordlines extend substantially in parallel with one another and correspond to first and second rows which neighbor one another. The first wordline is coupled to access gates of access transistors along the first row. The second wordline is coupled to access gates of access transistors along the second row. Nearest edges of the first and second wordlines include at least one wing which extends laterally outward from a sidewall of one of the first and second wordlines towards a sidewall the other of the first and second wordlines.

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Tainan, Taiwan

Nai-Chao Su