Trench MOSFET and method of manufacturing same
First Claim
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1. A trench MOSFET, comprising a trench region on a semiconductor substrate, the substrate containing:
- a heavily doped drain region of a first conduction type;
a lightly doped drain region of the first conduction type;
a channel body region of a second conduction type; and
a source region of the first conduction type, the regions being formed in this order and adjacent to each other, the trench region being covered with, and insulated from, the source region.
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Abstract
A trench MOSFET of the present invention has a trench region on a semiconductor substrate. The semiconductor substrate contains: a substrate which is a p-type heavily doped drain region; an epitaxial layer which is a p-type lightly doped drain region; a n-type body region; and a p-type source diffusion region, the regions being formed in this order. Further, a source diffusion region which is insulated from the trench region is provided to cover the trench region. The trench MOSFET has a reduced ON resistance.
26 Citations
14 Claims
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1. A trench MOSFET, comprising a trench region on a semiconductor substrate,
the substrate containing: - a heavily doped drain region of a first conduction type;
a lightly doped drain region of the first conduction type;
a channel body region of a second conduction type; and
a source region of the first conduction type, the regions being formed in this order and adjacent to each other,the trench region being covered with, and insulated from, the source region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- a heavily doped drain region of a first conduction type;
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11. A method of manufacturing a trench MOSFET including a trench region on a semiconductor substrate,
the substrate containing: - a heavily doped drain region of a first conduction type;
a lightly doped drain region of the first conduction type;
a channel body region of a second conduction type; and
a source region of the first conduction type, the regions being formed in this order and so that adjacent regions are in contact with each other,the method comprising the sequential steps of;
forming an insulating film on the trench region;
providing an amorphous silicon layer on the trench region on which the insulating film is formed and on the channel region; and
crystallizing the amorphous silicon layer, to form the source region. - View Dependent Claims (12, 13)
- a heavily doped drain region of a first conduction type;
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14. A method of manufacturing a trench MOSFET including a trench region on a semiconductor substrate,
the substrate containing: - a heavily doped drain region of a first conduction type;
a lightly doped drain region of the first conduction type;
a channel body region of a second conduction type; and
a source region of the first conduction type, the regions being formed in this order and so that adjacent regions are in contact with each other,the method comprising the sequential steps of;
forming an insulating film on the trench region; and
providing a polysilicon layer on the trench region on which the insulating film is formed and on the channel region, to form the source region.
- a heavily doped drain region of a first conduction type;
Specification