# US 2014/0191324 A1 · Methods of forming bulk finfet devices by performing a recessing process on liner materials to define different fin heights and finfet devices with such recessed liner materials

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- Number: US 2014/0191324 A1
- Document ID: US20140191324A1
- Status: Published application
- Kind: A1
- Application number: 13/736,294
- Filed: 2013-01-08
- Published: 2014-07-10
- Earliest claimed: 2013-01-08
- Assignees: International Business Machines Corporation; Globalfoundries Inc.
- Applicants: Globalfoundries Inc.; International Business Machines Corporation
- Inventors: Xiuyu Cai; Ruilong Xie; Kangguo Cheng; Ali Khakifirooz
- Web page: https://patentgrep.com/patent/US20140191324A1

## CPC

- H10D 89/10: Integrated device layouts
- H10D 30/021: {of FETs having insulated gates [IGFET]}
- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H10D 30/60: Insulated-gate field-effect transistors [IGFET] (H10D30/40 takes precedence)
- H10D 30/62: Fin field-effect transistors [FinFET]
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

One method includes performing an etching process through a patterned mask layer to form trenches in a substrate that defines first and second fins, forming liner material adjacent the first fin to a first thickness, forming liner material adjacent the second fin to a second thickness different from the first thickness, forming insulating material in the trenches adjacent the liner materials and above the mask layer, performing a process operation to remove portions of the layer of insulating material and to expose portions of the liner materials, performing another etching process to remove portions of the liner materials and the mask layer to expose the first fin to a first height and the second fin to a second height different from the first height, performing another etching process to define a reduced-thickness layer of insulating material, and forming a gate structure around a portion of the first and second fin.

## Claims

### Claim 1

A method of forming a FinFET device, comprising:
forming a patterned hard mask layer above a semiconducting substrate;
performing at least one first etching process through said patterned hard mask layer to form a plurality of trenches in said semiconducting substrate that define at least first and second fins;
forming liner material adjacent to at least said first fin to a first thickness;
forming liner material adjacent to at least said second fin to a second thickness that is different from said first thickness;
forming a layer of insulating material in said trenches adjacent said liner materials and above said patterned hard mask layer;
performing at least one process operation to remove portions of said layer of insulating material and to expose portions of said liner materials;
performing at least one second etching process to remove portions of said liner materials and said patterned hard mask layer, wherein removal of said liner materials results in exposing said first fin to a first height and said second fin to a second height that is different from said first height;
performing at least one third etching process on said layer of insulating material to thereby define a reduced-thickness layer of insulating material; and
forming a gate structure around a portion of said first fin and said second fin.

### Claim 2 (depends on 1)

The method of claim 1, wherein said patterned hard mask layer is comprised of silicon nitride, said liner material is comprised of aluminum oxide and said layer of insulating material is comprised of silicon dioxide.

### Claim 3 (depends on 1)

The method of claim 1, wherein performing said process operation comprises performing a chemical mechanical polishing process operation.

### Claim 4 (depends on 1)

The method of claim 1, wherein said first thickness is greater than said second thickness and said first height is greater than said second height.

### Claim 5 (depends on 1)

The method of claim 1, wherein said first thickness is less than said second thickness and said first height is less than said second height.

### Claim 6 (depends on 1)

The method of claim 1, wherein said liner material positioned adjacent said first fin comprises multiple layers of liner material, said liner material positioned adjacent said second fin comprises a single layer of liner material, said first thickness is greater than said second thickness and said first height is greater than said second height.

### Claim 7 (depends on 1)

The method of claim 1, wherein said liner material positioned adjacent said first fin comprises a single layer of liner material, said liner material positioned adjacent said second fin comprises a single layer of liner material, said first thickness is greater than said second thickness and said first height is greater than said second height.

### Claim 8 (depends on 1)

The method of claim 1, wherein said liner materials are made of the same material.

### Claim 9 (depends on 1)

The method of claim 1, wherein said second etching process results in said liner material adjacent said first fin having a first generally U-shaped liner positioned at a bottom of each of said trenches adjacent said first fin that exposes said first fin to said first height.

### Claim 10 (depends on 9)

The method of claim 9, wherein said first generally U-shaped liner comprises a plurality of spaced-apart generally upstanding substantially vertically oriented legs that define a first liner cavity.

### Claim 11 (depends on 9)

The method of claim 9, wherein said second etching process results in said liner material adjacent said second fin having a second generally U-shaped liner positioned at a bottom of each of said trenches adjacent said second fin that exposes said second fin to said second height.

### Claim 12 (depends on 11)

The method of claim 11, wherein said first generally U-shaped liner comprises a plurality of spaced-apart generally upstanding substantially vertically oriented legs that define a second liner cavity.

### Claim 13 (depends on 10)

The method of claim 10, wherein the entirety of said reduced-thickness layer of insulating material within each of said trenches adjacent said first fin is positioned entirely within said first liner cavity.

### Claim 14 (depends on 12)

The method of claim 12, wherein the entirety of said reduced-thickness layer of insulating material within each of said trenches adjacent said second fin is positioned entirely within said second liner cavity.

### Claim 15 (depends on 1)

The method of claim 1, wherein said gate structure is comprised of a silicon dioxide gate insulation layer and a polysilicon gate electrode positioned above said gate insulation layer.

### Claim 16 (depends on 1)

The method of claim 1, wherein said gate structure comprises a gate insulation layer comprised of a high-k insulating material and a gate electrode comprised of at least one layer of metal.

### Claim 17

A method of forming a FinFET device, comprising:
forming a patterned hard mask layer above a semiconducting substrate;
performing at least one first etching process through said patterned hard mask layer to form a plurality of trenches in said semiconducting substrate that define at least first and second fins;
forming a first liner layer in said plurality of trenches, above said hard mask and adjacent to at least said first and second fins;
performing a second etching process to remove at least portions of said first liner layer positioned adjacent said second fin;
forming a second liner layer above said first liner layer and adjacent to at least said second fin;
forming a layer of insulating material in said trenches above said first and second liner layers and above said patterned hard mask layer;
performing a process operation to remove portions of said layer of insulating material and to expose portions of at least said second liner layer;
performing at least one third etching process to remove portions of said first and second liner layers and said patterned hard mask layer, wherein removal of portions of said first and second liner layers results in exposing said first fin to a first height and exposing said second fin to a second height that is less than said first height;
performing at least one fourth etching process on said layer of insulating material to thereby define a reduced-thickness layer of insulating material; and
forming a gate structure around a portion of said first fin and said second fin.

### Claim 18 (depends on 17)

The method of claim 17, wherein said patterned hard mask layer is comprised of silicon nitride, said first and second liner layers are comprised of aluminum oxide and said layer of insulating material is comprised of silicon dioxide.

### Claim 19 (depends on 17)

The method of claim 17, wherein said first and second liner layers have the same approximate thickness.

### Claim 20 (depends on 17)

The method of claim 17, wherein said first and second liner layers are made of the same material.

### Claim 21 (depends on 17)

The method of claim 17, wherein said third etching process results in said first and second liner layers positioned at a bottom of each of said trenches adjacent said first fin defining a first generally U-shaped dual liner configuration that exposes said first fin to said first height.

### Claim 22 (depends on 21)

The method of claim 21, wherein said first generally U-shaped dual liner configuration comprises a plurality of spaced-apart generally upstanding substantially vertically oriented legs that define a first liner cavity.

### Claim 23 (depends on 21)

The method of claim 21, wherein said third etching process results in said second liner layer positioned at a bottom of each of said trenches adjacent said first fin defining a first generally U-shaped single liner configuration that exposes said second fin to said second height.

### Claim 24 (depends on 21)

The method of claim 21, wherein said first generally U-shaped liner comprises a plurality of spaced-apart generally upstanding substantially vertically oriented legs that define a second liner cavity.

### Claim 25

A FinFET device, comprising;
a plurality of trenches formed in a semiconducting substrate that define at least a first fin having a first height and a second fin having a second height, wherein said first and second heights are different;
a first local isolation region positioned in a bottom of each of a plurality of trenches that define said first fin, said first local isolation region comprising a first generally U-shaped liner material having a plurality of spaced apart generally upstanding vertically oriented legs that define, in part, a first cavity, said legs of said first generally U-shaped liner material having a first thickness;
a second local isolation region positioned in a bottom of each of a plurality of trenches that define said second fin, said second local isolation region comprising a second generally U-shaped liner material having a plurality of spaced apart generally upstanding vertically oriented legs that define, in part, a second cavity, said legs of said second generally U-shaped liner material having a second thickness that is different than said first thickness;
a layer of insulating material positioned at least partially in said first and second cavities; and
a gate structure positioned around a portion of said first and second fins.

### Claim 26 (depends on 25)

The device of claim 25, wherein said semiconducting substrate is comprised of silicon.

### Claim 27 (depends on 25)

The device of claim 25, wherein said layer of insulating material is positioned entirely within one of said cavities.

### Claim 28 (depends on 25)

The device of claim 25, wherein said gate structure is comprised of a silicon dioxide gate insulation layer and a polysilicon gate electrode positioned above said gate insulation layer.

### Claim 29 (depends on 25)

The device of claim 25, wherein said gate structure is comprised of a gate insulation layer comprised of a high-k insulating material and a gate electrode comprised of at least one layer of metal.

### Claim 30 (depends on 25)

The device of claim 25, wherein said trenches have at least one of substantially vertical sidewalls, sloped sidewalls or curved sidewalls.

### Claim 31 (depends on 25)

The device of claim 25, wherein said first thickness is greater than said second thickness and said first height is greater than said second height.

### Claim 32 (depends on 25)

The device of claim 25, wherein said first thickness is less than said second thickness and said first height is less than said second height.

### Claim 33 (depends on 25)

The device of claim 25, wherein said liner material positioned adjacent said first fin comprises multiple layers of liner material, said liner material positioned adjacent said second fin comprises a single layer of liner material, said first thickness is greater than said second thickness and said first height is greater than said second height.

### Claim 34 (depends on 25)

The device of claim 25, wherein said liner material positioned adjacent said first fin comprises a single layer of liner material, said liner material positioned adjacent said second fin comprises a single layer of liner material, said first thickness is greater than said second thickness and said first height is greater than said second height.