Non-volatile memory and method for fabricating the same

Abstract

A non-volatile memory is provided. The memory comprises a substrate, a dielectric layer, a conductive layer, an isolation layer, a buried bit line, a tunneling dielectric layer, a charge trapping layer, a barrier dielectric layer and a word line. Wherein, the dielectric layer is disposed on the substrate. The conductive layer is disposed on the dielectric layer. The isolation layer is disposed on the substrate and adjacent to the dielectric layer and the conductive layer. The buried bit line is disposed in the substrate and underneath the isolation layer. The tunneling dielectric layer is disposed on both the substrate and the sidewalls of the conductive layer and the isolation layer. The charge trapping layer is disposed on the tunneling dielectric layer and the barrier dielectric layer is disposed on the charge trapping layer. The word line is disposed on the substrate, crisscrossing with the buried bit line.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a memory, and more particularly, to a non-volatile memory and a method for fabricating the same. [0003] 2. Description of the Related Art [0004] The non-volatile memory is characterized by maintaining the stored data even when the power is down, and has thus become a mandatory device in many electronic products for providing normal operation of the electronic products when booted. Thus, the non-volatile memory has been widely used device in personal computer (PC) and other electronic equipment. [0005] In a conventional non-volatile memory, a stacked layer made of oxide-nitride-oxide (ONO layer) is disposed between a gate and a substrate. Wherein, the nitride layer, used as a film layer where the charges are trapped in, is also known as a charge trapping layer, and the memory cell, whose charge trapping layer is made of such material, is called Nitride Read Only Memory. [0006]FIG. 1 s...

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Benefits of technology

[0009] Accordingly, an object of the present invention is to provide a method for fabricating a non-volatile memory capable of preventing cross interference of two bits in the single memory cell of the non-volatile memory, such that the reliability of the memory device is enhanced.

[0028] Additionally, the bottom width of the angled isolation layer formed according to the present invention is less than the bottom width of the film layer below it, and the angled isolation layer can be used as an etch mask for removing the unnecessary film layers during the process, which is called a self-aligned process. Therefore, the self-aligned process mentioned above can produce an accurate pattern without forming a mask layer to cover the to-be-removed film layer or other process.

Problems solved by technology

However, when programming a conventional 2 bits non-volatile memory, two bits in the same memory cell are conditioned by each other, which may cause problems.

In addition, the cross interference of two bits in the single memory cell mentioned above may substantially implicate the device operation and even deteriorate the device reliability.

Therefore, when erasing the memory cell, the distribution curve formed when injecting the hot electrons into the charge trapping layer can not match with the electron distribution curve, thus the erasing will take more time and worse, the whole content of the memory cell may not be totally erased.

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