US 8,476,701 B2Granted

Semiconductor device with gate electrode including a concave portion

AssigneeRenesas Electronics Corporation

InventorsTakehiro Ueda, Hiroshi Kawaguchi

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Abstract

A semiconductor device includes a transistor that has a trench formed in an element forming region of a substrate, a gate insulating film formed on side faces and a bottom face of the trench, a gate electrode formed on the gate insulating film so as to bury the trench, a source region formed on one side in the gate longitude direction, which is formed on the surface of the substrate, and a drain region formed on the other side in the gate longitude direction. Here, the gate electrode is formed so as to be exposed also on the substrate outside the trench, and the gate electrode is disposed so as to cover upper portions of both ends of the trench and so as to form at least one concave portion having a depth reaching the substrate in a center portion.

Claims28

Dependent claims

A semiconductor device comprising:

a substrate that includes an element forming region that is partitioned by an element isolation insulating film;
and
a transistor that includes:
a trench formed in said element forming region of said substrate;
a gate insulating film formed on side faces and a bottom face of said trench;
a gate electrode formed on said gate insulating film so as to bury said trench and on said substrate outside said trench so as to be exposed;
a source region formed on one side of said gate electrode, which is disposed on a surface of said substrate, in a gate longitude direction;
and
a drain region formed on another side of said gate electrode in said gate longitude direction,
wherein a longer direction of said trench is abreast of said gate longitude direction,
wherein at least both ends of an edge of an opening of said trench in said gate longitude direction are covered with said exposed part of said gate electrode,
wherein said gate electrode has at least one concave portion having a depth reaching a surface of said substrate,
wherein said concave portion extends in a direction which intersects said gate longitude direction in a planar view,
wherein said concave portion overlaps with a part of said trench, a part of said edge of said opening, and a part of said surface of said substrate located along said part of said edge in a planar view, and
wherein said part of said edge and said part of said surface are not covered with said gate electrode.

12 more elements

A semiconductor device comprising:

a substrate that includes an element forming region that is partitioned by an element isolation insulating film;
and
a transistor that includes:
a trench formed in said element forming region of said substrate;
a gate insulating film formed on side faces and a bottom face of said trench;
a gate electrode formed on said gate insulating film so as to bury said trench and on said substrate outside said trench so as to be exposed;
a source region formed on one side of said gate electrode, which is disposed on a surface of said substrate, in a gate longitude direction;
and
a drain region founed on the other side of said gate electrode in said gate longitude direction,
wherein a longer direction of said trench is abreast of said gate longitude direction,
wherein at least both ends of an edge of an opening of said trench in said gate longitude direction are covered with said exposed part of said gate electrode,
wherein said gate electrode has at least one concave portion having a depth reaching a surface of said substrate,
wherein said concave portion extends in a direction which intersects said gate longitude direction in a planar view,
wherein said concave portion overlaps with a part of said trench, a part of said edge of said opening, and a part of said surface of said substrate located along said part of said edge in a planar view, and
wherein said part of said edge and said part of said surface are not covered with said gate electrode,
and
wherein a film thickness of said gate insulating film formed in lower portions from a predetermined height of said side faces of said trench is thicker than a film thickness of said gate insulating film formed along upper portions from said predetermined height of said side faces of said trench and is equal to or more than a film thickness of said gate insulating film on said bottom face.

14 more elements

A device comprising:

a substrate including a trench having a first upper side and a second upper side;
and
a transistor that includes:
a gate electrode that includes:
a first portion formed in the trench;
and
a second portion that is formed outside of the trench, the second portion including a first side and a second side, the first side and the second side covering the first upper side and the second upper side of the trench, respectively;
a source region formed adjacent to the first side of the second portion of the gate electrode;
and
a drain region formed adjacent to the second side of the second portion of the gate electrode,
wherein at least one portion of the second portion of the gate electrode is discontinuous in a channel region,
wherein at least both ends of an edge of an opening of said trench in a gate longitude direction are covered with said second portion of said gate electrode,
wherein said gate electrode has at least one concave portion having a depth reaching a surface of said substrate,
wherein said concave portion extends in a direction which intersects said gate longitude direction in a planar view,
wherein said concave portion overlaps with a part of said trench, a part of said edge of said opening, and a part of said surface of said substrate located along said part of said edge in a planar view, and
wherein said part of said edge and said part of said surface are not covered with said gate electrode.

13 more elements

A semiconductor device comprising:

a substrate that includes an element forming region that is partitioned by an element isolation insulating film;
and
a transistor that includes:
a trench formed in said element forming region of said substrate;
a gate insulating film formed on side faces and a bottom face of said trench;
a gate electrode formed on said gate insulating film so as to bury said trench;
a source region formed on one side of said gate electrode, which is disposed on a surface of said substrate, in a gate longitude direction;
a drain region formed on another side of said gate electrode in said gate longitude direction;
and
a channel region formed between said source region and said drain region in said gate longitude direction,
wherein said channel region extends in a first direction intersecting said gate longitude direction in a planar view,
wherein a depth direction of side faces of said trench, formed between said source region and said drain region, being parallel with said gate longitude direction, is a width direction of said gate,
wherein said gate insulating film is formed on said side faces and said bottom face of said trench,
wherein said gate electrode is formed on said gate insulating film so as to bury said trench, and
wherein said gate electrode includes a portion between said source region and said drain region in said gate longitude direction which does not reach a surface of said substrate.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/067,243Filed 18 May 2011
Priority: JP 2010-11573119 May 2010
Published: US 2011/0284951 A124 Nov 2011
Granted: 2 Jul 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H10D 30/60
Field-effect transistors [FET]: insulated-gate field-effect transistors [IGFET]
H10D 62/292
Of igfets: non-planar channels of IGFETs
H10D 30/024
Of FETs having insulated gates [IGFET]: of fin field-effect transistors [FinFET]
H10D 30/6211
Fin field-effect transistors [FinFET]: having fin-shaped semiconductor bodies integral with the bulk semiconductor substrates