Method for manufacturing nonvolatile memory device
OwnerSeok Leeinventor
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Abstract
Disclosed is a method for manufacturing a nonvolatile memory device having an SONOS double gate. The method can improve credibility, as well as device characteristics, by increasing the thickness of the gate insulation film, i.e., the dielectric film, in the SONOS structure of the cell region, as well as in the peripheral circuit region. The method can cause oxidation even to the cell region during gate light etching by etching nitride film in the cell region prior to the gate light etching. This increases the thickness of the gate insulation film of SONOS structure on the lower corner of the gate electrode in the cell region and improves device characteristics and credibility.
Claims7
A method for manufacturing a nonvolatile memory device comprising the steps of:
- forming a first oxide film, a nitride film, and a second oxide film on a silicon substrate having a cell region and a peripheral circuit region to form SONOS structure in the cell region;
- selectively removing the second oxide film and the nitride film in the region having no SONOS structure;
- forming a third oxide film on the first oxide film in the region having no SONOS structure;
- forming a gate conductive film on the resulting substrate;
- etching the gate conductive film and the third and second oxide films to form a gate electrode in the cell region and the peripheral circuit region, respectively;
- removing the nitride film from the lower corner of the gate electrode, which has been formed in the cell region;
- and
- performing gate light oxidation to the resulting substrate so that etching damage during formation of the gate electrode is removed.
Dependencies are inferred from the claim text.