Method of manufacturing semiconductor device having trench-gate transistor
First Claim
1. A method of manufacturing a semiconductor device, comprising:
- a first step of forming an STI (Shallow Trench Isolation) region includes a first insulating film and an active region surrounded by the STI region on a semiconductor substrate so that an upper end of the first insulating film is lapped on an upper end of the active region and so as to include a shoulder part almost perpendicular to the semiconductor substrate in a direction crossing the active region;
a second step of forming a second insulating film and a third insulating film in this order on an entire surface including the shoulder part;
a third step of forming a fourth insulating film on the third insulating film, the fourth insulating film serving as a hard mask when a gate trench is formed;
a fourth step of performing a dry etching using the third insulating film as a stopper, and forming an opening in the fourth insulating film, the opening corresponding to a width of the gate trench;
a fifth step of sequentially removing the third insulating film and the second insulating film exposed to a bottom of the opening; and
a sixth step of forming the gate trench in the semiconductor substrate using the fourth insulating film as a mask in a direction almost parallel to the active region, forming the gate trench using the shoulder part of the STI region as a mask in an extension direction of the gate trench, and leaving a thin film part that is a part of the semiconductor substrate between the gate trench and the STI region.
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Abstract
A method of manufacturing a semiconductor device includes: a first step of forming an STI region and an active region surrounded by the STI region on a semiconductor substrate; a second step of forming a protection film protecting a shoulder part of the STI region in a boundary between the active region and the STI region; a third step of forming a gate trench in the active region so as to leave a part of the semiconductor substrate located between a side surface of the STI region and a side surface of the gate trench; a fourth step of forming a gate insulating film on the side surface of the gate trench; a fifth step of forming a gate electrode, at least a part of the gate electrode being buried in the gate trench; and a sixth step of forming a source region and a drain region in regions located on both sides of the gate trench in an extension direction of the gate trench, respectively, so that the part of the semiconductor substrate functions as a channel region.
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Citations
20 Claims
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1. A method of manufacturing a semiconductor device, comprising:
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a first step of forming an STI (Shallow Trench Isolation) region includes a first insulating film and an active region surrounded by the STI region on a semiconductor substrate so that an upper end of the first insulating film is lapped on an upper end of the active region and so as to include a shoulder part almost perpendicular to the semiconductor substrate in a direction crossing the active region; a second step of forming a second insulating film and a third insulating film in this order on an entire surface including the shoulder part; a third step of forming a fourth insulating film on the third insulating film, the fourth insulating film serving as a hard mask when a gate trench is formed; a fourth step of performing a dry etching using the third insulating film as a stopper, and forming an opening in the fourth insulating film, the opening corresponding to a width of the gate trench; a fifth step of sequentially removing the third insulating film and the second insulating film exposed to a bottom of the opening; and a sixth step of forming the gate trench in the semiconductor substrate using the fourth insulating film as a mask in a direction almost parallel to the active region, forming the gate trench using the shoulder part of the STI region as a mask in an extension direction of the gate trench, and leaving a thin film part that is a part of the semiconductor substrate between the gate trench and the STI region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of manufacturing a semiconductor device, comprising:
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a first step of forming an STI region and an active region surrounded by the STI region on a semiconductor substrate; a second step of forming a protection film protecting a shoulder part of the STI region in a boundary between the active region and the STI region; a third step of forming a gate trench in the active region so as to leave a part of the semiconductor substrate located between a side surface of the STI region and a side surface of the gate trench; a fourth step of forming a gate insulating film on the side surface of the gate trench; a fifth step of forming a gate electrode, at least a part of the gate electrode being buried in the gate trench; and a sixth step of forming a source region and a drain region in regions located on both sides of the gate trench in an extension direction of the gate trench, respectively, so that the part of the semiconductor substrate functions as a channel region. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A semiconductor device comprising:
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a semiconductor substrate; an STI region formed in the semiconductor substrate; a gate trench formed in the semiconductor substrate; a gate electrode formed in the gate trench; and a channel region located between a side surface of the STI region and a side surface of the gate trench; wherein the side surface of the gate trench is almost perpendicular to the semiconductor substrate.
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Specification