US6146970A — Capped shallow trench isolation and method of for…

Claim 1

Independent Claim 185 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate; forming a trench region within the substrate, the trench region having a top portion and a bottom portion; forming a first liner region within the trench region; depositing a first trench fill material within the trench region after forming the first liner region, wherein the first trench fill material comprises silicon and oxygen; removing a portion of the first trench fill material to form a first trench plug region within the trench region; removing a portion of the first liner region to expose a portion of the substrate; depositing a second trench fill material overlying the first trench plug region, wherein the second trench fill material is different from the first trench fill material and the second trench fill material comprises silicon and nitrogen; and removing a portion of the second trench fill material to form a second trench plug region, wherein the second trench plug region overlies the first trench plug region and a portion of the second trench plug region contacts the exposed portion of the substrate.

Claim 2

Independent Claim 185 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate; forming a trench region within the substrate, the trench region having a top portion and a bottom portion; forming a first liner region within the trench region; depositing a first trench fill material within the trench region after forming the first liner region, wherein the first trench fill material comprises silicon and oxygen; removing a portion of the first trench fill material to form a first trench plug region within the trench region; removing a portion of the first liner region to expose a portion of the substrate; depositing a second trench fill material overlying the first trench plug region, wherein the second trench fill material is different from the first trench fill material and the second trench fill material comprises silicon and nitrogen; and removing a portion of the second trench fill material to form a second trench plug region, wherein the second trench plug region overlies the first trench plug region and a portion of the second trench plug region contacts the exposed portion of the substrate.

Claim 3

Dependent Claim 21 words

The method of claim 1 wherein the step of depositing the second trench fill material comprises: depositing a silicon nitride layer.

Claim 4

Dependent Claim 20 words

The method of claim 1 wherein the step of depositing the second trench fill material comprises: depositing an oxynitride layer.

Claim 5

Dependent Claim 93 words

The method of claim 1 wherein the trench region separates a first active area from a second active area, wherein the method further comprises: exposing one of the active areas to an active area processing environment wherein this active area processing environment is capable of eroding the first trench plug region over time but is incapable of substantially eroding the second trench plug region that overlies the first first trench plug region, the second trench plug region preventing the first trench plug region from substantial erosion due to the active area processing environment.

Claim 6

Dependent Claim 69 words

The method of claim 1 wherein the trench region separates a first active area from a second active area, wherein the method further comprises: forming a MOS device in the first active area using first active area processing steps; and forming a nonvolatile device within the second active area using second active area processing steps, at least some of which being different from the first active area processing steps.

Claim 7

Dependent Claim 117 words

The method of claim 1 wherein the trench region separates a first active area from a second active area, and a second trench region separates the second active area from a third active area, wherein the method further comprises: forming a first type of device in the first active area using first active area processing steps; forming a second type of device within the second active area using second active area processing steps; and forming a third type of device within the third active area using third active area processing steps, wherein the second trench plug region protects the first trench plug region during one or more of the first, second, and third active area processing steps.

Claim 8

Dependent Claim 58 words

The method of claim 1 wherein the step of removing the portion of the first trench fill material comprises: polishing the first trench fill material; and exposing the first trench fill material to an etch process to recess a top surface of the first trench fill material within the trench region to form the first trench plug region.

Claim 9

Dependent Claim 36 words

The method of claim 7 wherein the step of removing the portion of the second trench fill material comprises: polishing the second trench fill material to form a capping region over the first trench plug region.

Claim 10

Independent Claim 207 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate having a top surface; forming a pad dielectric over the substrate; forming a masking layer over the pad dielectric; etching at least one trench region through the masking layer and pad dielectric and into the substrate; forming a first liner region within the at least one trench region; depositing a first trench fill material, wherein the first trench fill material includes an oxide; removing top portions of the first trench fill material to form a first trench plug region made of the first trench fill material; etching the first liner region and the first trench plug region to form a recessed trench plug region and to expose a portion of the substrate; forming a second liner region adjacent to the exposed portion of the substrate; depositing a second trench fill material, wherein the second trench fill material includes a layer selected from a group consisting of a nitride layer and an oxynitride layer; removing top portions of the second trench fill material to expose the masking layer; and removing the masking layer and the pad dielectric to expose active areas of the semiconductor structure adjacent the at least one trench region.

Claim 11

Independent Claim 207 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate having a top surface; forming a pad dielectric over the substrate; forming a masking layer over the pad dielectric; etching at least one trench region through the masking layer and pad dielectric and into the substrate; forming a first liner region within the at least one trench region; depositing a first trench fill material, wherein the first trench fill material includes an oxide; removing top portions of the first trench fill material to form a first trench plug region made of the first trench fill material; etching the first liner region and the first trench plug region to form a recessed trench plug region and to expose a portion of the substrate; forming a second liner region adjacent to the exposed portion of the substrate; depositing a second trench fill material, wherein the second trench fill material includes a layer selected from a group consisting of a nitride layer and an oxynitride layer; removing top portions of the second trench fill material to expose the masking layer; and removing the masking layer and the pad dielectric to expose active areas of the semiconductor structure adjacent the at least one trench region.

Claim 12

Dependent Claim 22 words

The method of claim 9 wherein the one of either the masking layer or the second trench fill material is silicon nitride.

Claim 13

Dependent Claim 43 words

The method of claim 9 wherein the step of removing top portions of the second trench fill material comprises: forming a dielectric sidewall spacer around a sidewall of the masking layer, the dielectric sidewall spacer being made of the second trench fill material.

Claim 14

Dependent Claim 25 words

The method of claim 9 wherein the first trench fill material mostly comprises silicon dioxide and the second trench fill material mostly comprises silicon nitride.

Claim 15

Dependent Claim 25 words

The method of claim 9 wherein the first trench fill material mostly comprises silicon dioxide and the second trench fill material mostly comprises silicon oxynitride.

Claim 16

Dependent Claim 73 words

The method of claim 9 wherein the at least one trench region is adjacent a first active area and a second active area, wherein the method further comprises: forming a MOS device in the first active area using first active area processing steps; and forming a nonvolatile device within the second active area using second active area processing steps, at least some of which being different from the first active area processing steps.

Claim 17

Dependent Claim 110 words

The method of claim 9 wherein the at least one trench region is adjacent a first active area, a second active area, and a third active area, wherein the method further comprises: forming a first type of device in the first active area using first active area processing steps; forming a second type of device within the second active area using second active area processing steps; and forming a third type of device within the third active area using third active area processing steps, wherein the second trench fill material protects the first trench fill material during one or more of the first, second, and third active area processing steps.

Claim 18

Dependent Claim 25 words

The method of claim 9 wherein the step of forming the first liner region results in oxidation of a top surface of the masking layer.

Claim 19

Dependent Claim 19 words

The method of claim 9 wherein the second liner region comprises one of either oxynitride or undoped silicon dioxide.

Claim 20

Dependent Claim 20 words

The method of claim 9 wherein the step of removing top portions of the first trench fill material comprises polishing.

Claim 21

Dependent Claim 41 words

The method of claim 9 wherein the step of etching the first trench plug region and the first liner region is further characterized as using a dry plasma environment to etch the first trench plug region and the first liner region.

Claim 22

Dependent Claim 20 words

The method of claim 9 wherein the step of removing top portions of the second trench fill material comprises polishing.

Claim 23

Dependent Claim 23 words

The method of claim 9 wherein the first trench fill material comprises one of either tetraethylorthosilicate (TEOS) or high density plasma (HDP) oxide.

Claim 24

Dependent Claim 19 words

The method of claim 9 wherein the first trench fill material is densified after formation by a densification step.

Claim 25

Dependent Claim 14 words

The method of claim 9 wherein the masking layer is polysilicon or amorphous silicon.

Claim 26

Independent Claim 185 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate; forming a trench region within the substrate; forming a first liner region within the trench region; depositing a first trench fill material within the trench region after forming the first liner region, wherein the first trench fill material comprises silicon and oxygen; removing a portion of the first trench fill material to form a first trench plug region within the trench region; removing a portion of the first liner region to expose a portion of the substrate; forming a second liner region adjacent the exposed portion of the substrate; depositing a second trench fill material overlying the first trench plug region, wherein the second trench fill material is different from the first trench fill material and the second trench fill material comprises silicon and nitrogen; and removing a portion of the second trench fill material to form a second trench plug region, wherein the second trench plug region overlies the first trench plug region and the second liner region lies between the second trench plug region and the substrate.

Claim 27

Independent Claim 185 words

A method for forming a semiconductor structure, the method comprising the steps of: providing a substrate; forming a trench region within the substrate; forming a first liner region within the trench region; depositing a first trench fill material within the trench region after forming the first liner region, wherein the first trench fill material comprises silicon and oxygen; removing a portion of the first trench fill material to form a first trench plug region within the trench region; removing a portion of the first liner region to expose a portion of the substrate; forming a second liner region adjacent the exposed portion of the substrate; depositing a second trench fill material overlying the first trench plug region, wherein the second trench fill material is different from the first trench fill material and the second trench fill material comprises silicon and nitrogen; and removing a portion of the second trench fill material to form a second trench plug region, wherein the second trench plug region overlies the first trench plug region and the second liner region lies between the second trench plug region and the substrate.

Claim 28

Dependent Claim 21 words

The method of claim 24 wherein the step of depositing the second trench fill material comprises: depositing a silicon nitride layer.

Claim 29

Dependent Claim 20 words

The method of claim 24 wherein the step of depositing the second trench fill material comprises: depositing an oxynitride layer.

Claim 30

Dependent Claim 92 words

The method of claim 24 wherein the trench region separates a first active area from a second active area, wherein the method further comprises: exposing one of the active areas to an active area processing environment wherein this active area processing environment is capable of eroding the first trench plug region over time but is incapable of substantially eroding the second trench plug region that overlies the first trench plug region, the second trench plug region preventing the first trench plug region from substantial erosion due to the active area processing environment.

Claim 31

Dependent Claim 69 words

The method of claim 24 wherein the trench region separates a first active area from a second active area, wherein the method further comprises: forming a MOS device in the first active area using first active area processing steps; and forming a nonvolatile device within the second active area using second active area processing steps, at least some of which being different from the first active area processing steps.

Claim 32

Dependent Claim 117 words

The method of claim 24 wherein the trench region separates a first active area from a second active area, and a second trench region separates the second active area from a third active area, wherein the method further comprises: forming a first type of device in the first active area using first active area processing steps; forming a second type of device within the second active area using second active area processing steps; and forming a third type of device within the third active area using third active area processing steps, wherein the second trench plug region protects the first trench plug region during one or more of the first, second, and third active area processing steps.

Claim 33

Dependent Claim 58 words

The method of claim 24 wherein the step of removing the portion of the first trench fill material comprises: polishing the first trench fill material; and exposing the first trench fill material to an etch process to recess a top surface of the first trench fill material within the trench region to form the first trench plug region.

Claim 34

Dependent Claim 36 words

The method of claim 30 wherein the step of removing the portion of the second trench fill material comprises: polishing the second trench fill material to form a capping region over the first trench plug region.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2003-11-14	2004-05-15	2004-11-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2007-11-14	2008-05-15	2008-11-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2011-11-14	2012-05-15	2012-11-14	$7700.00	Window Closed / Lapsed

Capped shallow trench isolation and method of formation

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