Isolation structure, semiconductor device having the same, and method for fabricating the isolation structure
First Claim
Patent Images
1. A semiconductor device, comprising:
- a substrate having a top surface;
an isolation structure comprising;
a trench formed in the substrate;
an oxide layer formed on a sidewall of the trench;
a filler formed on the oxide layer to fill a part of inside of the trench; and
an additional oxide layer filling an upper portion of the trench,a buried layer formed to abut the trench and having a depth shallower than a depth of the trench;
a first well region and a second well region formed on the buried layer, the first well region abutting against the second well region and the first well region having a depth equal to a depth of the second well region;
a third well region formed in the first well region and having a same conductivity type as the first well region;
a drain region formed in the second well region;
a source region formed in the third well region;
a gate insulating layer formed on the first well region and the second well region; and
a gate electrode formed on the gate insulating layer.
3 Assignments
0 Petitions
Accused Products
Abstract
An isolation structure of a semiconductor, a semiconductor device having the same, and a method for fabricating the isolation structure are provided. An isolation structure of a semiconductor device may include a trench formed in a substrate, an oxide layer formed on a bottom surface and an inner sidewall of the trench, a filler formed on the oxide layer to fill a part of inside of the trench, and a fourth oxide layer filling an upper portion of the filler of the trench to a height above an upper surface of the trench, an undercut structure being formed on a boundary area between the inner sidewall and the oxide layer.
14 Citations
20 Claims
-
1. A semiconductor device, comprising:
-
a substrate having a top surface; an isolation structure comprising; a trench formed in the substrate; an oxide layer formed on a sidewall of the trench; a filler formed on the oxide layer to fill a part of inside of the trench; and an additional oxide layer filling an upper portion of the trench, a buried layer formed to abut the trench and having a depth shallower than a depth of the trench; a first well region and a second well region formed on the buried layer, the first well region abutting against the second well region and the first well region having a depth equal to a depth of the second well region; a third well region formed in the first well region and having a same conductivity type as the first well region; a drain region formed in the second well region; a source region formed in the third well region; a gate insulating layer formed on the first well region and the second well region; and a gate electrode formed on the gate insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A semiconductor device, comprising:
-
an isolation structure comprising; at least one trench formed in a substrate; a composite layer comprising an oxide layer and a nitride layer formed on a sidewall of the trench; a filler formed on the composite layer; and an additional oxide layer formed on the filler, a buried layer formed in the substrate and disposed to abut the trench having a depth larger than a depth of the buried layer; a first well region and a second well region formed on the buried layer, the first well region abutting against the second well region and having a depth equal to a depth of the second well region; a source region formed in the first well region; a drain region formed in the second well region; a gate insulating layer formed on the first well region and the second well region; and a gate electrode formed on the gate insulating layer, wherein the isolation structure is in direct contact with the first well region and the second well region. - View Dependent Claims (14, 15, 16, 17)
-
-
18. A semiconductor device, comprising:
-
a substrate having a top surface; a first well region of a first conductivity type formed in the substrate; a second well region of a second conductivity type abutting against the first well region; a source region formed in the first well region; a drain region formed in the second well region; an isolation structure to enclose the first well region and the second well region, the isolation structure comprising; at least one trench formed in the substrate; a polysilicon layer filled in the at least one trench; and an oxide layer fully enclosing the polysilicon layer; a field oxide layer formed on one side or both sides of the at least one trench, a buried layer formed to abut the at least one trench and having a depth smaller than a depth of the trench; a gate insulating layer formed on the first well region and the second well region; and a gate electrode formed on the gate insulating layer. - View Dependent Claims (19, 20)
-
Specification