US5604159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a contact structure
Assignee: NXP USA Inc
•
Filing: 1994-01-31
•
Granted: 1997-02-18
•
Expires: 2014-01-31
Abstract
Abstract The horizontal surface area required to contact semiconductor devices, in integrated circuits fabricated with trench isolation, is minimized without degrading contact resistance by utilizing the vertical surface area of the trench sidewall. A trench isolation region (40) is formed within the semiconductor substrate (12). A doped region (74, 96) is then formed such that it abuts the trench sidewall (24). A portion (56, 110) of the trench sidewall (24), abutting the doped region (74, 96), is then exposed by forming a recess (55, 112) within the trench isolation region (40). A conductive member (66, 114, 118) is then formed such that it is electrically coupled to the doped region (74, 96) along the exposed trench sidewall, as well as along the major surface (13) of the semiconductor substrate (12), and results in the formation of a low resistance contact structure.
Inventors
- 👤 Kent J. Cooper
- 👤 Scott S. Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:54
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011
Claims Analysis
Total Claims: 70
Claim 1
Independent Claim
145 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench isolation region within a first portion of the semiconductor substrate, the trench isolation region comprising a trench and a trench plug lying within the trench, the trench having a trench sidewall; forming a source/drain region for a first transistor, the source/drain region lying within a second portion of the semiconductor substrate; wherein as a result of forming the trench isolation region and the source/drain region, the source/drain region abuts the trench sidewall; forming a recess within a portion of the trench isolation region; and forming a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting the trench sidewall.
Claim 2
Independent Claim
145 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench isolation region within a first portion of the semiconductor substrate, the trench isolation region comprising a trench and a trench plug lying within the trench, the trench having a trench sidewall; forming a source/drain region for a first transistor, the source/drain region lying within a second portion of the semiconductor substrate; wherein as a result of forming the trench isolation region and the source/drain region, the source/drain region abuts the trench sidewall; forming a recess within a portion of the trench isolation region; and forming a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting the trench sidewall.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein the step of forming the gate electrode for the second transistor comprises the step of depositing a layer of amorphous silicon.
Claim 4
Dependent Claim
48 words
The method of claim 1, wherein the step of forming the trench isolation region comprises the steps of: etching the semiconductor substrate to form the trench; depositing a trench fill material within the trench; and removing a portion of the trench fill material to form the trench plug.
Claim 5
Dependent Claim
24 words
The method of claim 1, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 6
Dependent Claim
26 words
The method of claim 1, wherein the step of forming the gate electrode for the second transistor comprises the step of depositing a layer of polysilicon.
Claim 7
Dependent Claim
33 words
The method of claim 1, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode for the second transistor to diffuse a dopant into the semiconductor substrate.
Claim 8
Dependent Claim
27 words
The method of claim 1, wherein the step of forming the gate electrode for the second transistor comprises the step of depositing a conductive layer of material.
Claim 9
Independent Claim
185 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a trench fill material within the trench; removing a portion of the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; and forming a gate electrode for a second transistor overlying the trench plug and the source/drain region, wherein a portion of the gate electrode for the second transistor abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 10
Independent Claim
185 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a trench fill material within the trench; removing a portion of the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; and forming a gate electrode for a second transistor overlying the trench plug and the source/drain region, wherein a portion of the gate electrode for the second transistor abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 11
Dependent Claim
33 words
The method of claim 8, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode for the second transistor to diffuse a dopant into the semiconductor substrate.
Claim 12
Dependent Claim
26 words
The method of claim 8, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a layer of polysilicon.
Claim 13
Dependent Claim
30 words
The method of claim 10, wherein the step of forming the gate electrode for the second transistor further comprises the step of doping the layer of polysilicon using ion implantation.
Claim 14
Dependent Claim
22 words
The method of claim 8, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer.
Claim 15
Dependent Claim
25 words
The method of claim 12, wherein the step of depositing the dielectric layer is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 16
Dependent Claim
25 words
The method of claim 12, wherein the step of forming the source/drain region comprises the step of implanting a n-type dopant into the semiconductor substrate.
Claim 17
Dependent Claim
27 words
The method of claim 8, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a layer of amorphous silicon.
Claim 18
Dependent Claim
26 words
The method of claim 8, wherein the step of removing the portion of the trench fill material comprises the step of: polishing the trench fill material.
Claim 19
Dependent Claim
26 words
The method of claim 16, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 20
Dependent Claim
27 words
The method of claim 16, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a conductive layer of material.
Claim 21
Dependent Claim
24 words
The method of claim 16, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the contact region.
Claim 22
Dependent Claim
24 words
The method of claim 8, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 23
Dependent Claim
24 words
The method of claim 8, further comprising the step of forming a trench liner within the trench prior to depositing the trench fill material.
Claim 24
Dependent Claim
32 words
The method of claim 21, wherein the step of forming the trench liner comprises the step of oxidizing a portion of the semiconductor substrate to form a layer of thermal silicon dioxide.
Claim 25
Dependent Claim
27 words
The method of claim 22, wherein the step of exposing the portion of the trench sidewall is further characterized as etching a portion of the trench liner.
Claim 26
Dependent Claim
90 words
The method of claim 8, wherein the step of forming the source/drain region for the first transistor is further characterized as forming the source/drain region to have a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and wherein the first portion of the source/drain region abuts the trench sidewall.
Claim 27
Independent Claim
194 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a trench fill material within the trench; removing a portion of the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; forming a recess within a portion of the trench isolation region, the recess underlying the contact region; and forming a gate electrode for a second transistor overlying the trench plug and the source/drain region, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting a portion of the trench sidewall.
Claim 28
Independent Claim
194 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a trench fill material within the trench; removing a portion of the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; forming a recess within a portion of the trench isolation region, the recess underlying the contact region; and forming a gate electrode for a second transistor overlying the trench plug and the source/drain region, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting a portion of the trench sidewall.
Claim 29
Dependent Claim
26 words
The method of claim 25, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a layer of polysilicon.
Claim 30
Dependent Claim
30 words
The method of claim 26, wherein the step of forming the gate electrode for the second transistor further comprise the step of doping the layer of polysilicon using ion implantation.
Claim 31
Dependent Claim
22 words
The method of claim 25, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer.
Claim 32
Dependent Claim
25 words
The method of claim 28, wherein the step of depositing the dielectric layer is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 33
Dependent Claim
27 words
The method of claim 25, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a layer of amorphous silicon.
Claim 34
Dependent Claim
25 words
The method of claim 25, wherein the step of forming the source/drain region comprises the step of implanting a n-type dopant into the semiconductor substrate.
Claim 35
Dependent Claim
26 words
The method of claim 25, wherein the step of removing the portion of the trench fill material comprises the step of: polishing the trench fill material.
Claim 36
Dependent Claim
26 words
The method of claim 32, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 37
Dependent Claim
27 words
The method of claim 32, wherein the step of forming the gate electrode for the second transistor comprises the step of: depositing a conductive layer of material.
Claim 38
Dependent Claim
24 words
The method of claim 32, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the contact region.
Claim 39
Dependent Claim
24 words
The method of claim 25, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 40
Dependent Claim
24 words
The method of claim 25, further comprising the step of forming a trench liner within the trench prior to depositing the trench fill material.
Claim 41
Dependent Claim
32 words
The method of claim 37, wherein the step of forming the trench liner comprises the step of oxidizing a portion of the semiconductor substrate to form a layer of thermal silicon dioxide.
Claim 42
Dependent Claim
23 words
The method of claim 38, wherein the step of forming the recess is further characterized as etching a portion of the trench liner.
Claim 43
Independent Claim
132 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts the trench sidewall; forming a trench plug within the trench to form a trench isolation region; exposing a portion of the trench sidewall after forming the trench plug; and forming a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 44
Independent Claim
132 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts the trench sidewall; forming a trench plug within the trench to form a trench isolation region; exposing a portion of the trench sidewall after forming the trench plug; and forming a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 45
Dependent Claim
24 words
The method of claim 40, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 46
Dependent Claim
29 words
The method of claim 40, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode to diffuse a dopant into the semiconductor substrate.
Claim 47
Dependent Claim
36 words
The method of claim 40, wherein the step of forming the trench plug comprises the steps of: depositing a trench fill material within the trench; and polishing the trench fill material to form the trench plug.
Claim 48
Dependent Claim
26 words
The method of claim 43, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 49
Independent Claim
197 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts the trench sidewall; depositing a trench fill material within the trench; polishing the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; depositing a layer of polysilicon, the layer of polysilicon abutting the exposed portion of the trench sidewall; patterning the layer of polysilicon to form a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode for the second transistor abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 50
Independent Claim
197 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts the trench sidewall; depositing a trench fill material within the trench; polishing the trench fill material to form a trench plug within the trench, wherein the trench and the trench plug form a trench isolation region; forming a resist mask overlying the trench plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; depositing a layer of polysilicon, the layer of polysilicon abutting the exposed portion of the trench sidewall; patterning the layer of polysilicon to form a gate electrode for a second transistor overlying the trench plug, wherein a portion of the gate electrode for the second transistor abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 51
Dependent Claim
24 words
The method of claim 45, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 52
Dependent Claim
29 words
The method of claim 43, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode to diffuse a dopant into the semiconductor substrate.
Claim 53
Dependent Claim
25 words
The method of claim 45, wherein the step of depositing the trench fill material is further characterized as depositing a dielectric layer within the trench.
Claim 54
Dependent Claim
25 words
The method of claim 48, wherein the step of depositing the dielectric layer is further characterized as depositing a dielectric layer comprising silicon and oxygen.
Claim 55
Independent Claim
176 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a dielectric layer within the trench; polishing the dielectric layer to form a dielectric plug in the trench, wherein the trench and the dielectric plug form a trench isolation region; forming a resist mask overlying the dielectric plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; and forming a gate electrode for a second transistor overlying the dielectric plug and the source/drain region, wherein a portion of the gate electrode abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 56
Independent Claim
176 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a dielectric layer within the trench; polishing the dielectric layer to form a dielectric plug in the trench, wherein the trench and the dielectric plug form a trench isolation region; forming a resist mask overlying the dielectric plug to define a contact region, the contact region overlying the trench sidewall; exposing a portion of the trench sidewall underlying the contact region; and forming a gate electrode for a second transistor overlying the dielectric plug and the source/drain region, wherein a portion of the gate electrode abuts the exposed portion of the trench sidewall and is electrically shorted to the source/drain region.
Claim 57
Dependent Claim
22 words
The method of claim 50, wherein the step of forming the gate electrode comprises the step of: depositing a layer of polysilicon.
Claim 58
Dependent Claim
29 words
The method of claim 50, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode to diffuse a dopant into the semiconductor substrate.
Claim 59
Dependent Claim
25 words
The method of claim 50, wherein the step of depositing the dielectric layer is further characterized as depositing a dielectric layer using ozone and tetraethylorthosilicate.
Claim 60
Dependent Claim
23 words
The method of claim 50, wherein the step of forming the gate electrode comprises the step of: depositing a layer of amorphous silicon.
Claim 61
Dependent Claim
24 words
The method of claim 50, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 62
Dependent Claim
90 words
The method of claim 50, wherein the step of forming the source/drain region for the first transistor is further characterized as forming the source/drain region to have a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and wherein the first portion of the source/drain region abuts the trench sidewall.
Claim 63
Independent Claim
189 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a dielectric layer within the trench; polishing the dielectric layer to form a dielectric plug in the trench, wherein the trench and the dielectric plug form a trench isolation region; forming a resist mask overlying the dielectric plug to define a contact region, the contact region overlying the trench sidewall; forming a recess within a portion of the trench isolation region, the recess underlying the contact region; and forming a gate electrode for a second transistor overlying the dielectric plug and the source/drain region, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting a portion of the trench sidewall.
Claim 64
Independent Claim
189 words
A method for forming a contact structure in an integrated circuit comprising the steps of: providing a semiconductor substrate; forming a trench within a first portion of the semiconductor substrate, the trench having a trench sidewall; forming a source/drain region for a first transistor within a second portion of the semiconductor substrate; wherein as a result of forming the trench and the source/drain region, the source/drain region abuts a portion of the trench sidewall; depositing a dielectric layer within the trench; polishing the dielectric layer to form a dielectric plug in the trench, wherein the trench and the dielectric plug form a trench isolation region; forming a resist mask overlying the dielectric plug to define a contact region, the contact region overlying the trench sidewall; forming a recess within a portion of the trench isolation region, the recess underlying the contact region; and forming a gate electrode for a second transistor overlying the dielectric plug and the source/drain region, wherein a portion of the gate electrode for the second transistor lies within the recess and is electrically shorted to the source/drain region abutting a portion of the trench sidewall.
Claim 65
Dependent Claim
22 words
The method of claim 57, wherein the step of forming the gate electrode comprises the step of: depositing a layer of polysilicon.
Claim 66
Dependent Claim
29 words
The method of claim 57, wherein the step of forming the source/drain region comprises the step of annealing the gate electrode to diffuse a dopant into the semiconductor substrate.
Claim 67
Dependent Claim
25 words
The method of claim 57, wherein the step of depositing the dielectric layer is further characterized as depositing a dielectric layer using ozone and tetraethylorthosilicate.
Claim 68
Dependent Claim
23 words
The method of claim 57, wherein the step of forming the gate electrode comprises the step of: depositing a layer of amorphous silicon.
Claim 69
Dependent Claim
24 words
The method of claim 57, wherein the step of forming the source/drain region comprises the step of implanting a dopant into the semiconductor substrate.
Claim 70
Dependent Claim
90 words
The method of claim 57, wherein the step of forming the source/drain region for the first transistor is further characterized as forming the source/drain region to have a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and wherein the first portion of the source/drain region abuts the trench sidewall.
References Cited (Backward Citations)
US4318751A
Cited
US4446476A
Cited
US4519128A
Cited
US4733287A
Cited
US4534824A
Cited
US4549927A
Cited
US4824793A
Cited
US4797373A
Cited
US4656497A
Cited
US4808555A
Cited
US4884123A
Cited
US4939567A
Cited
US5003375A
Cited
US5100823A
Cited
US4876217A
Cited
US5015594A
Cited
US4945069A
Cited
US5108938A
Cited
US5106777A
Cited
US5362678A
Cited
US5064777A
Cited
US5488010A
Cited
US5112772A
Cited
US5457339A
Cited
US5315142A
Cited
US5275965A
Cited
US5268330A
Cited
US5482869A
Cited
US5422294A
Cited
US5389559A
Cited
US5395786A
Cited
US5460987A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-18 | 2000-08-19 | 2001-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-18 | 2004-08-19 | 2005-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-18 | 2008-08-19 | 2009-02-18 | $7700.00 | Window Closed / Lapsed |