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US 2012/0256264 A1Published application
Semiconductor device and fabrication method
AssigneeFujitsu Semiconductor Limited
InventorsMasaki Haneda, Yuka Kase, Masanori Terahara, Takayuki Aoyama
Life of this patent
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Abstract
A semiconductor device includes a semiconductor substrate including a well having a first conductivity type defined by a device isolation region, a gate insulating film formed on the semiconductor substrate, a gate electrode formed on the gate insulating film and including a first side surface and a second side surface facing the first side surface, and a first side wall insulating film formed on the first side surface and a second side wall insulating film formed on the second side surface.
Claims17
A semiconductor device comprising:
- a semiconductor substrate including a well having a first conductivity type, the well being defined by a device isolation region;
- a gate insulating film formed on the semiconductor substrate;
- a gate electrode formed on the gate insulating film, the gate electrode including a first side surface and a second side surface facing the first side surface;
- and
- a first side wall insulating film formed on the first side surface and a second side wall insulating film formed on the second side surface, wherein
- the semiconductor substrate includes a mesa structure located below the first side wall insulating film, the gate electrode and the second side wall insulating film,
- the mesa structure includes a first side surface and a second side surface,
- a first semiconductor layer having the second conductivity type that form a source region is formed outside of the first side surface of the mesa structure, with the first semiconductor layer being connected to the semiconductor substrate on the first side surface,
- a second semiconductor layer having the second conductivity type that form a drain region is formed outside of the second side surface of the mesa structure, with the second semiconductor layer being connected to the semiconductor substrate on the second side surface,
- a first embedded insulating region formed of a first insulating film is formed beneath the first semiconductor layer and a second embedded insulating region formed of the first insulating film is formed beneath the second semiconductor layer, and
- a second insulating film is formed between the first embedded insulating region and the first side surface of the mesa structure, and a third insulating film is formed between the second embedded insulating region and the second side surface of the mesa structure.
8 more elements
A method for fabricating a semiconductor device, the method comprising:
- forming a gate electrode on a first region of a semiconductor substrate formed of a first semiconductor, forming a first side wall insulating film on a first side surface of the gate electrode and forming a second side wall insulating film on a second side surface of the gate electrode;
- forming a first opening part and a second opening part with the first region interposed therebetween;
- forming a first insulating film on side surfaces and a bottom surface of the first opening part and also on side surfaces and a bottom surface of the second opening part;
- removing the first insulating film while allowing at least parts of the first insulating film to remain on the side surfaces of the first and the second opening parts;
- forming a first semiconductor layer and a second semiconductor layer in the first opening part and the second opening part, respectively, the first and the second semiconductor layers being formed of a second semiconductor having etching selectivity to the first semiconductor;
- removing the first insulating film from the side surface of the first opening part and also from the side surface of the second opening part;
- forming a third semiconductor layer and a fourth semiconductor layer on the first semiconductor layer and the second semiconductor layer, respectively, after having removed the first insulating film from the side surface of the first opening part and also from the side surface of the second opening part, the third and the fourth semiconductor layers being formed of the first semiconductor;
- exposing respective parts of the first semiconductor layer and the second semiconductor layer after having formed the third semiconductor layer and the fourth semiconductor layer on the first semiconductor layer and the second semiconductor layer, respectively;
- removing the first and second semiconductor layers to form a third opening part and a fourth opening part after having exposed the respective parts of the first semiconductor layer and the second semiconductor layer;
- forming a second insulating film in the third opening part and the fourth opening part;
- and
- implanting an impurity element in the third semiconductor layer and the fourth semiconductor layer to form a first diffusion region and a second diffusion region, respectively.
9 more elements
Dependencies are inferred from the claim text.