Flash memory and forming method thereof

Abstract

The invention discloses a flash memory and a forming method thereof. The flash memory comprises a semiconductor substrate. The semiconductor substrate comprises a source line floating gate region anda plurality of word line bit line regions. The source line floating gate region is located between adjacent word line bit line regions. Each word line bit line region comprises a first word line bit line region and a second word line bit line region. The first word line bit line region is located between the second word line bit line region and the source line floating gate region. A floating gatestructure is positioned on the source line floating gate region semiconductor substrate. A first sidewall is arranged on the floating gate structure. A source line layer is positioned between the floating gate structure and the first side wall. A first word line structure is located on the first word line bit line region and comprises a first word line oxide layer. A second word line structure islocated on the second word line bit line area. The second word line structure comprises a second word line oxidation layer. The second word line oxidation layer covers the side wall of the first wordline structure and a second word line oxidation layer on the surface of the semiconductor substrate in the second word line bit line region. The performance of the flash memory is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a flash memory and a forming method thereof. Background technique [0002] Flash memory is an important device in integrated circuit products. The main feature of flash memory is that it can keep stored information for a long time without applying voltage. Flash memory has the advantages of high integration, fast access speed and easy wiring, so it is widely used. [0003] Flash memory is classified into two types: stack gate flash memory and split gate flash memory. The stacked gate flash memory has a floating gate and a control gate above the floating gate. The stacked gate flash memory has the problem of over-supply lines. Different from the stacked gate flash memory, the split gate flash memory forms a word line as a source line gate on one side of the floating gate. The split-gate flash memory can effectively avoid the over-source line effect. [0004] Howeve...

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Problems solved by technology

[0004] However, the performance of existing split-gate flash memory is poor

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