Semiconductor device and method of manufacturing semiconductor device

Patent metadata

Field	Value
Publication number	US-9842912-B2
Application number	US-201615178574-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Aug 19, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A semiconductor device with a high radiation tolerance is provided. A semiconductor device comprising a semiconductor substrate, a first body region and a second body region provided on a front surface side of the semiconductor substrate, a neck portion provided between the first body region and the second body region, a first source region formed within the first body region and a second source region formed within the second body region, a first gate electrode provided to face the first body region between the first source region and the neck portion, a second gate electrode provided to face the second body region between the second source region and the neck portion, and an insulating film continuously provided between the first gate electrode and the semiconductor substrate, between the second gate electrode and the semiconductor substrate, and on the front surface side of the neck portion, is provided.

First claim

What is claimed is:

1. A semiconductor device comprising:
a semiconductor substrate of a first conductivity type;
a first body region and a second body region having a second conductivity type and provided in a front surface side of the semiconductor substrate;
a neck portion of the first conductivity type provided between the first body region and the second body region;
a first source region having the first conductivity type and formed within the first body region and a second source region having the first conductivity type and formed within the second body region;
a first gate electrode facing the first body region between the first source region and the neck portion and a second gate electrode facing the second body region between the second source region and the neck portion; and
an insulating film continuously provided between the first gate electrode and the semiconductor substrate, between the second gate electrode and the semiconductor substrate, and on a front surface side of the neck portion, wherein
an end portion of the first body region is provided to face an end portion of the first gate electrode, and an end portion of the second body region is provided to face an end portion of the second gate electrode, on a front surface of the semiconductor substrate,
the first body region and the second body region each have a protruding portion which protrudes to the neck portion side beyond an end portion of the body region on the front surface of the semiconductor substrate, and
a tilt of a tangential line of the protruding portion relative to the front surface of the semiconductor substrate gradually increases from a side of the end portion toward a tip of the protruding portion, in a cross section which is perpendicular to the front surface of the semiconductor substrate.

2. The semiconductor device according to claim 1 , wherein
a length A with which the protruding portion protrudes to the side of the neck portion beyond the end portion of each body region on the front surface of the semiconductor substrate is in a range of an equation below,

0
<
A
<

L
2

-

2
⁢

⁢
K
⁢

⁢

ɛ
0

q

⁢

N
A

N
D

⁡

(

N
A

+

N
D

)

⁢

ϕ
bi

[

Equation
⁢

⁢
1

]

where L indicates a distance between the first gate electrode and the second gate electrode, K indicates the permittivity of vacuum, ε 0 indicates a relative permittivity of the semiconductor substrate, q indicates the elementary charge, N A indicates an acceptor concentration of a p-type conductive region of each of the body regions and the neck portion, N D indicates a donor concentration of an n-type conductive region of each of the body regions and the neck portion, and φ bi indicates a built-in potential generated in a depletion layer between each of the body regions and the neck portion.

3. The semiconductor device according to claim 1 , wherein the protruding portion has a recessed portion of a convex shape on a back surface side of the semiconductor substrate between the front surface of the semiconductor substrate and a tip of the protruding portion which protrudes to the neck portion side the most.

4. The semiconductor device according to claim 3 , wherein a depth of the recessed portion in the direction of depth of the semiconductor substrate is equal to a width of the recessed portion in the direction parallel to the front surface of the semiconductor substrate.

5. The semiconductor device according to claim 1 , wherein a thickness of at least a portion of the insulating film opposite the neck portion is different from a thickness of the insulating film opposite the first gate electrode and the second gate electrode.

6. A method of manufacturing a semiconductor device comprising:
by implanting impurities of a second conductivity type on a front surface side of a semiconductor substrate of a first conductivity type, forming a first body region and a second body region of the second conductivity type, and a neck portion of the first conductivity type provided between the first body region and the second body region;
forming a first source region of the first conductivity type within the first body region and a second source region of the first conductivity type within the second body region;
forming an insulating film on the front surface of the semiconductor substrate;
forming a first gate electrode opposite the first body region between the first source region and the neck portion and a second gate electrode opposite the second body region between the second source region and the neck portion, on a front surface side of the insulating film;
forming a protruding portion which protrudes to the neck portion side beyond an end portion of each of the first body region and the second body region on the front surface of the semiconductor substrate in first body region and the second body region, after forming the first gate electrode and the second gate electrode.

7. The method of manufacturing according to claim 6 , wherein, in the forming of the first gate electrode and the second gate electrode, each of the first and second gate electrodes is formed on an inner side of the body region with respect to the end por

Assignees

• Fuji Electric Co Ltd

Inventors

• Tatemichi Shuhei
• Takenoiri Shunji
• Inoue Masanori
• Kumagai Yuji
• Kuboyama Satoshi
• Mizuta Eiichi

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P32/1406

  by ion implantation · CPC title

• H10P32/171

  being group IV material · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10P30/21

  of electrically active species · CPC title