Semiconductor device and its manufacturing method
AssigneeKabushiki Kaisha Toshiba
InventorsTakeo Furuhata, Ichiro Mizushima, Akiko Sekihara, Motoya Kishida, Tsubasa Harada, Takashi Nakao
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Abstract
A semiconductor device comprises a semiconductor substrate; a trench formed in the semiconductor substrate or in a layer deposited on the semiconductor substrate; a first conductive layer deposited in the trench and having a recess in the top surface thereof; a buried layer which buries the recess of the first conductive layer and which is made of a material having a melting point lower than that of the first conductive layer; and a second conductive layer formed on the buried layer inside the trench and electrically connected to the first conductive layer.
Claims14
A semiconductor device comprising:
- a semiconductor substrate including a trench having an inner wall;
- a first storage node electrode formed in the trench, having a recess with a V-shaped cross section in a top surface thereof;
- a capacitor insulating film located between the first storage node electrode and the inner wall;
- a buried layer formed on the recess, wherein the buried layer is electrically conductive;
- a second storage node electrode formed on the buried layer in the trench;
- a collar insulating film located between the second storage node electrode and the inner wall;
- and
- a buried strap formed above the second storage node electrode in the trench.
A semiconductor device comprising:
- a semiconductor substrate having a semiconductor layer of a first conduction type, including a trench having an inner surface;
- a gate electrode formed on the semiconductor layer via a gate insulating film;
- a source region and a drain region each of a second conduction type formed on a surface layer of the semiconductor layer;
- and
- a trench capacitor electrically connected to one of the source and drain regions, the trench capacitor including
- a capacitor insulating film formed on the inner surface, the capacitor insulating film located in a lower portion of the trench,
- a collar insulating film formed above the capacitor insulating film in the inner surface, and
- a storage node electrode buried in the trench, and electrically connected to one of the source and drain regions, the storage node electrode including
- a first conductive layer formed on the capacitor insulating film in the trench to bury the lower portion, and having a recess at the upper surface with a V-shaped cross section a second conductive layer buried in the recess, a third conductive layer formed on the collar insulating film in the trench, and a fourth conductive layer formed above the third conductive layer in the trench.
A semiconductor device comprising:
- a semiconductor substrate including a trench having an inner wall;
- a first storage node electrode formed in the trench including a seam formed in the first storage node electrode, an entire length of the seam being parallel to the inner wall, and a V-shaped recess formed in a top surface of the first storage node electrode in contact with the seam;
- a capacitor insulating film located between the first storage node electrode and the inner wall;
- a buried layer formed on the recess, the buried layer including an electrically conducting material;
- a second storage node electrode formed on the buried layer in the trench;
- a collar insulating film located between the second storage node electrode and the inner wall;
- and
- a buried strap formed above the second storage node electrode in the trench.
Dependencies are inferred from the claim text.