Semiconductor device and method of manufacturing same
AssigneeRenesas Electronics Corporation
InventorsHideki Aono, Tetsuya Yoshida, Makoto Ogasawara, Shinichi Okamoto
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Abstract
To provide a semiconductor device having improved reliability. An element isolation region comprised mainly of silicon oxide is buried in a trench formed in a semiconductor substrate. The semiconductor substrate in an active region surrounded by the element isolation region has thereon a gate electrode for MISFET via a gate insulating film. The gate electrode partially extends over the element isolation region and the trench has a nitrided inner surface. Below the gate electrode, fluorine is introduced into the vicinity of a boundary between the element isolation region and a channel region of MISFET.
Claims8
A semiconductor device comprising:
- a semiconductor substrate having a first element isolation region and an active region adjacent to the first element isolation region;
- and
- a MISFET having:
- a gate insulating film formed on the semiconductor substrate in the active region,
- a gate electrode formed on the gate insulating film,
- a source region formed in the semiconductor substrate in the active region and formed on one side of the gate electrode,
- a drain region formed in a second portion of the semiconductor substrate in the active region and formed on the other side of the gate electrode, and
- a channel region formed in the semiconductor substrate in the active region and formed between the source region and the drain region,
- wherein the semiconductor substrate in the first element isolation region has a first trench,
- wherein a first insulating film is buried in the first trench,
- wherein the first insulating film is overlapped with a part of the gate electrode,
- wherein the first insulating film has:
- a first portion into which fluorine is implanted, and located beneath the part of the gate electrode, and
- a second portion located lower side of the first insulating film than the first portion in cross-section view, and
- wherein a concentration of fluorine in the first portion is higher than a concentration of fluorine in the second portion.
Dependencies are inferred from the claim text.