Patent EP0338480A1 successfully refreshed from Google Patents.
EP0338480A1
Expired / Lapsed
EP
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Method for filling trenches from a seed layer
Assignee: Motorola Solutions Inc
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Filing: 1989-04-17
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Granted: —
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Expires: 2009-04-17
Abstract
Abstract Filled trenches useful in semiconductor devices for isolation or other purposes are provided by etching a trench (18) in the semiconductor substrate (10), lining the trench (18) with a material (24) (e.g., silicon dioxide), covering the first material (24) with a seed layer (26) (e.g., polysilicon) for nucleating a further material (34), removing a part (26u) of the seed layer (26) on the first material (24) in an upper part of the trench (18), and then filling the trench (18) by selectively depositing the further material (34) (e.g., polysilicon) on the remaining seed layer. Thermally grown silicon dioxide is convenient for the first material (24). The first material (24) and seed layer (26) may extend over the substrate surface (12). The upper portion (26u) of the seed layer (26) is conveniently removed by first covering the seed layer (26) with a mask (28) (e.g., photoresist) and then etching back the mask (28) to expose the seed layer (26) above the substrate surface (12) and in the upper portion of the trench (18), leaving part (30) of the mask (28) in the lower portion of the trench (18). The exposed portion (26u) of the seed layer (26) is then etched away. The remaining portion of the mask (28) is removed before growing the trench filling material (34) on the remaining part (24c) of the seed layer (24) in the trench (18).
Inventors
- 👤 Francine Y. Robb
- 👤 Frederick J. Robinson
- 👤 Bridget Svechovsky
- 👤 Thomas E. Wood
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 22:20
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/041; H10W10/40
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
146 words
A process for forming poly filled trenches, comprising: providing a substrate (10) having a principal surface (12); etching a trench (18) having a sidewall (22) extending a predetermined depth into the substrate (10) from the substrate surface (12); covering at least the sidewall (22) with a dielectric (24); covering the dielectric (24) with a poly layer (26) having a first thickness (27) and extending over the substrate surface (12); at least partially removing the poly layer (26) from above the substrate surface (12) and completely removing the poly layer (26) from the dielectric (24) on an upper portion of the trench sidewall (22) leaving a remaining portion (26C) of the poly layer (26) on the dielectric (24) on a lower portion of the trench sidewall (22); and depositing further poly (34) on the remaining portion (26C) of the poly layer (26) to fill the trench (18).
Claim 2
Dependent Claim
146 words
A process for forming poly filled trenches, comprising: providing a substrate (10) having a principal surface (12); etching a trench (18) having a sidewall (22) extending a predetermined depth into the substrate (10) from the substrate surface (12); covering at least the sidewall (22) with a dielectric (24); covering the dielectric (24) with a poly layer (26) having a first thickness (27) and extending over the substrate surface (12); at least partially removing the poly layer (26) from above the substrate surface (12) and completely removing the poly layer (26) from the dielectric (24) on an upper portion of the trench sidewall (22) leaving a remaining portion (26C) of the poly layer (26) on the dielectric (24) on a lower portion of the trench sidewall (22); and depositing further poly (34) on the remaining portion (26C) of the poly layer (26) to fill the trench (18).
Claim 3
Dependent Claim
51 words
The process of claim 1 wherein the remaining portion (26C) of the poly layer (26) on the dielectric (24) on a lower portion of the trench sidewall (22) has a height along the sidewall (22) greater than the first thickness (27) and less than about seventy percent of the trench depth.
Claim 4
Dependent Claim
95 words
The process of claim 1 wherein the step of removing the poly layer (26) from the dielectric (24) on an upper portion of the trench sidewall (22) comprises, first, applying a masking layer (28) to cover the poly layer (26), second, partially removing the masking layer (28) to leave a portion(30) covering a first part (26C) of the poly layer (26) on a lower portion of the trench sidewall (22) and expose a second part (26U) of the poly layer (26) elsewhere and, third, etching away the second part (26U) of the poly layer (26).
Claim 5
Dependent Claim
60 words
The process of claim 3 wherein the step of partially removing the masking layer (28) comprises rendering an upper portion of the masking layer (28) intended to be removed soluble in a solvent while leaving the portion (30) covering the first part (26C) of the polylayer (26) on the lower part of the trench sidewall (22) insoluble to the solvent.
Claim 6
Dependent Claim
139 words
A process for forming isolation walls for electronic devices in a substrate, comprising: forming a trench (18) having a sidewall (22) and a bottom (20) extending into the substrate(10) a predetermined depth (19); lining at least the sidewall (22) of the trench (18) with a dielectric (24); forming on the dielectric (24) a polycrystalline semiconductor layer (26) having a first thickness (27); completely removing an upper portion (26U) of the polycrystalline semiconductor layer (26) from the dielectric (24) in the trench(18), leaving a lower portion (26C) of the polycrystalline semiconductor layer (26) on the dielectric (24) in the trench (18) extending up the dielectric (24) on the sidewall (22) a distance greater than the first thickness (27) and less than about seventy percent of the trench depth (19); and filling the trench (18) with a further polycrystalline semiconductor (34).
Claim 7
Dependent Claim
139 words
A process for forming isolation walls for electronic devices in a substrate, comprising: forming a trench (18) having a sidewall (22) and a bottom (20) extending into the substrate(10) a predetermined depth (19); lining at least the sidewall (22) of the trench (18) with a dielectric (24); forming on the dielectric (24) a polycrystalline semiconductor layer (26) having a first thickness (27); completely removing an upper portion (26U) of the polycrystalline semiconductor layer (26) from the dielectric (24) in the trench(18), leaving a lower portion (26C) of the polycrystalline semiconductor layer (26) on the dielectric (24) in the trench (18) extending up the dielectric (24) on the sidewall (22) a distance greater than the first thickness (27) and less than about seventy percent of the trench depth (19); and filling the trench (18) with a further polycrystalline semiconductor (34).
Claim 8
Dependent Claim
30 words
The process of claims 5 wherein the step of filling the trench (18) comprises selectively growing polycrystalline semiconductor (34) on the lower portion (26C) of the polycrystalline semiconductor layer (26).
Claim 9
Dependent Claim
55 words
The process of claim 5 wherein the trench (18) extends into the substrate (10) from a principal surface (12) thereof and the step of filling the trench(18) comprises selectively growing polycrystalline semiconductor (34) on the lower portion (26C) of the polycrystalline semiconductor layer (26) and not on the principal surface (12) of the substrate (10).
Claim 10
Dependent Claim
107 words
The process of claim 5 wherein the step of removing an upper portion (28U) of the polycrystalline semiconductor layer(26) on the dielectric (24), while leaving a lower portion (26C) of the polycrystalline semiconductor layer (26) in place on the dielectric (24) comprises forming a mask(28) at least partly filling the trench (18), then removing an upper part of the mask corresponding to an upper portion (26U) of the polycrystalline semiconductor layer (26) and leaving a lower part (30) of the mask(28) corresponding to the lower portion(26C) of the polycrystalline semiconductor layer (26), and then etching away the exposed upper portion (26U) of the polycrystalline semiconductor layer (26).
Claim 11
Dependent Claim
228 words
A process for filling a trench from a seed layer, comprising: providing a substrate (10) having a principal surface (12); etching a trench (18) having a sidewall (22) and bottom (20) extending a predetermined depth (19) into the substrate (10) from the principal surface (12); applying a seed layer (26) having a first thickness (27) to the sidewall (22); depositing a masking layer (28) which substantially fills the trench (18) and extends above the substrate surface (12); removing a first portion of the masking layer (28) above the substrate surface (12) and in an upper portion of the trench (18), leaving a second portion (30) of the masking layer(28) covering the seed layer (26) in a lower portion of the trench(18) to a height greater than the first thickness (27); completely removing the seed layer (26) from the sidewall (22) in the upper portion of the trench (18) while leaving a remaining portion (26C) of the seed layer (26) on the sidewall (22) in the lower portion of the trench (18), wherein the remaining portion (26C) of the seed layer (26) has a height measured along the sidewall (22) greater than the first thickness (27) and less than about seventy percent of the trench depth (19); and filling the trench (18) by depositing additional material (34) which nucleates on the remaining portion (26C) of the seed layer (26).
Claim 12
Dependent Claim
228 words
A process for filling a trench from a seed layer, comprising: providing a substrate (10) having a principal surface (12); etching a trench (18) having a sidewall (22) and bottom (20) extending a predetermined depth (19) into the substrate (10) from the principal surface (12); applying a seed layer (26) having a first thickness (27) to the sidewall (22); depositing a masking layer (28) which substantially fills the trench (18) and extends above the substrate surface (12); removing a first portion of the masking layer (28) above the substrate surface (12) and in an upper portion of the trench (18), leaving a second portion (30) of the masking layer(28) covering the seed layer (26) in a lower portion of the trench(18) to a height greater than the first thickness (27); completely removing the seed layer (26) from the sidewall (22) in the upper portion of the trench (18) while leaving a remaining portion (26C) of the seed layer (26) on the sidewall (22) in the lower portion of the trench (18), wherein the remaining portion (26C) of the seed layer (26) has a height measured along the sidewall (22) greater than the first thickness (27) and less than about seventy percent of the trench depth (19); and filling the trench (18) by depositing additional material (34) which nucleates on the remaining portion (26C) of the seed layer (26).
Claim 13
Dependent Claim
18 words
The process of claim 9 wherein the seed layer(26) and the additional material (34) comprises the same element.
References Cited (Backward Citations)
EP0097789A2
Cited
FR2588416A1
Cited
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