Acer Inc.

Te-Chih Chen

Ting-Chang Chang

Fu-Yen Jian

Shih-Ching Chen

Yong-En Syu

Chia-Sheng Lin

There is a method for enabling a SONOS transistor to be used as both a switch and a memory. FN tunneling is carried out through the source or drain of the transistor, so as to further change the state of electrons stored in an upper charge storage layer adjacent to the drain or source, and the variation in gate-induced drain leakage is used to recognize the memory state of the drain and source. A stable threshold voltage of the transistor is always maintained during this operation. The present invention enables one single transistor having dual features of switch and memory, while being provided with a two-bit memory effect, thus providing a higher memory density in comparison with a general transistor.

Method for enabling a SONOS transistor to be used as both a switch and a memory

One embodiment of the present invention provides an operation method of a memory device. The memory device includes a source, a drain, and a channel region between the source and the drain, a gate dielectric with a charge storage layer on the channel region, and a gate on the gate dielectric, wherein the source, the drain and the channel region are located in a substrate. The operation method includes the following steps: applying a reverse bias between the gate and the drain of the memory device to generate band-to-band hot holes in the substrate near the drain; injecting the band-to-band hot holes to a drain side of the charge storage layer; and performing a program/erase operation upon the memory device. The band-to-band hot holes in the drain side of the charge storage layer are not completely vanished by the program/erase operation.

Operation method of memory device

A method for operating a memory device is provided. In accordance with the method, the charges are stored in a source storage region, a drain storage region, and a channel storage region of a charge storage layer which respectively correspond to a source, a drain, and a channel of a SONOS transistor, thereby achieving 3-bit information storage in one cell. The channel storage region is programmed and erased by FN tunneling. Both of the source storage region and the drain storage region are programmed by channel hot electrons and erased by source-side or drain-side FN tunneling. The present invention can store three-bit data per cell, such that the storage density of the memory device can be substantially increased.

The present invention relates to a nonvolatile memory apparatus and a method of using a thin film transistor (TFT) as a nonvolatile memory by storing carriers in a body of the TFT, which operates a general TFT as a memory cell of a nonvolatile memory by manipulating the electrical characteristics of the TFT in order to integrate with other electrical components formed by TFTs, such as logic circuit or TFT-LCD pixel transistor, on the LCD panel without additional semiconductor manufacturing processes.

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Taipei Hsien, Taiwan

Te-Chih Chen