Protection element and fabrication method for the same
AssigneePanasonic Corporation
InventorsYukihiro Yamashita, Keita Takahashi
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Abstract
The protection element of the present invention is constructed of a MOS capacitor composed of a semiconductor substrate, an insulating film formed on the semiconductor substrate and a word line formed on the insulating film. A well region having a conductivity type opposite to that of the semiconductor substrate is formed in a portion of the semiconductor substrate constituting the MOS capacitor. If charge exceeding the breakdown voltage of the insulating film constituting the MOS capacitor is induced in the word line, the induced charge is released into either the semiconductor substrate or the well region depending on whether the induced charge is positive or negative.
Claims11
A protection element of a semiconductor device formed on a semiconductor substrate, the protection element comprising a MOS capacitor having the semiconductor substrate, an insulating film formed on the semiconductor substrate and a conductive film formed on the insulating film,
- wherein a first well region having a conductivity type opposite to that of the semiconductor substrate is formed in a portion of the semiconductor substrate constituting the MOS capacitor.
A fabrication method for a protection element of a nonvolatile semiconductor memory device having MONOS memory cells, the protection element comprising a MOS capacitor,
- wherein the MOS capacitor is formed by forming a well region having a conductivity type opposite to that of a semiconductor substrate in a protection element formation region of the semiconductor substrate, and then forming an insulating film and then a conductive film on the semiconductor substrate including the well region, and
- the conductive film is formed simultaneously with formation of a word line for the MONOS memory cells by extending the word line into the protection element formation region.
Dependencies are inferred from the claim text.