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.
Claims16
A semiconductor device comprising:
- 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.
A method of manufacturing a semiconductor device comprising:
- forming a trench in a semiconductor substrate or in a layer deposited on the semiconductor substrate;
- depositing a first conductive layer in the trench;
- etching a part of the first conductive layer in a relatively upper location in the trench;
- depositing an electrically conductive and burying-use material having a melting point lower than that of the first conductive layer on a recess that is produced in the top surface of the first conductive layer in the step of etching the first conductive layer;
- heating the burying-use material to a temperature higher than the melting point thereof and lower than the melting point of the first conductive layer;
- etching the burying-use material to remove the part thereof from the sidewall of the trench and maintain the part thereof near the recess;
- and
- depositing a second conductive layer on the burying-use material in the recess.
Dependencies are inferred from the claim text.