Vertical trench gate transistor semiconductor device and method for fabricating the same
AssigneePanasonic Corporation
InventorsShuji Mizokuchi, Kazuaki Tsunoda
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Abstract
A first region functioning as a transistor includes a drain region, a body region formed over the drain region, a source region formed over the body region and a trench formed through the body region and having a gate electrode buried therein. A source region is formed over the body region extending in a second region. The source region forming an upper edge of the trench is rounded.
Claims14
A method for fabricating a vertical trench gate transistor semiconductor device having a first portion functioning as a transistor and a second portion functioning as an electrical contact with a body region of the transistor and arranged adjacent to the first portion, comprising:
- a first step of forming a first drain region in the first portion and a second drain region in the second portion, and forming a first body region over the first drain region and a second body region over the second drain region;
- a second step of forming a trench in the first body region and the second body region;
- a third step of forming a first source region over the first body region;
- a fourth step of forming a second source region over the second body region;
- a fifth step of forming a gate within the trench so as to form a recessed part in an upper part of the trench after the second step;
- a sixth step of forming an insulating film for burying the recessed part after the fifth step;
- and
- a seventh step of removing an upper part of the insulating film and rounding an upper edge of a wall face of the recessed part,
- wherein the first source region and the second source region are formed so as to be electrically connected with each other.
A method for fabricating a vertical trench gate transistor semiconductor device having a first portion functioning as a transistor and a second portion functioning as an electrical contact with a body region of the transistor and arranged adjacent to the first portion, comprising:
- a first step of forming a first drain region in the first portion and a second drain region in the second portion, and forming a first body region over the first drain region and a second body region over the second drain region;
- a second step of forming a trench in the first body region and the second body region;
- a third step of forming a gate in the trench so as to form a recessed part in an upper part of the trench and so as to expose the second body region at a wall face of the recessed part;
- a fourth step of forming, in the recessed part, an additional electrode electrically connected to the second body region;
- a fifth step of forming a gate in the trench so as to form a recessed part in an upper part of the trench after the second step;
- a sixth step of forming an insulating film for burying the recessed part after the fifth step;
- and
- a seventh step of removing an upper part of the insulating film and rounding an upper edge of a wall face of the recessed part after the sixth step.
Dependencies are inferred from the claim text.