# US 10,483,361 B1 · Wrap-around-contact structure for top source/drain in vertical FETs

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- Number: US 10,483,361 B1
- Document ID: US10483361B1
- Status: Granted
- Kind: B1
- Application number: 16/115,955
- Filed: 2018-08-29
- Granted: 2019-11-19
- Earliest claimed: 2018-08-29
- Assignees: International Business Machines Corporation
- Applicants: International Business Machines Corporation
- Inventors: Choonghyun Lee; Christopher J. Waskiewicz; Alexander Reznicek; Hemanth Jagannathan
- Web page: https://patentgrep.com/patent/US10483361B1

## CPC

- H10D 64/252: {for vertical or pseudo-vertical devices}
- H10D 30/0212: {using self-aligned silicidation}
- H10D 30/025: {of vertical IGFETs (of VDMOS H10D30/0291; of vertical TFTs H10D30/0318)}
- H10D 30/63: Vertical IGFETs (H10D30/66 {, H10D30/6728, H10D30/689, H10D30/693} take precedence)
- H10D 30/6728: {Vertical TFTs}
- H10D 62/151: {of IGFETs (of IGFETs having LDD or DDD structure H10D30/601; of thin film transistors H10D30/6713)}
- H10D 64/015: {removing at least parts of gate spacers, e.g. disposable spacers}
- H10D 64/021: {using multiple gate spacer layers, e.g. bilayered sidewall spacers}
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10D 84/013: {Manufacturing their source or drain regions, e.g. silicided source or drain regions}
- H10D 84/0135: {Manufacturing their gate conductors}
- H10D 84/0149: {Manufacturing their interconnections or electrodes, e.g. source or drain electrodes}
- H10D 84/016: {the components including vertical IGFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 84/83: of only insulated-gate FETs [IGFET]
- H10D 64/01318: {the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN (comprising a layer of alloys of Si, Ge or C H10D64/01314)}
- H10D 64/667: {the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN workfunction layers (having lateral variation H10D64/671)}
- H10D 64/691: {comprising metallic compounds, e.g. metal oxides or metal silicates (insulators comprising nitrogen H10D64/693)}
- H10P 14/3411: {Silicon, silicon germanium or germanium}
- H10P 14/3466: {Crystal orientation}
- H10P 14/6334: {using decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition (deposition by physical ablation of a target H10P14/6329)}
- H10P 14/6339: {deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD}
- H10P 14/69392: {the material containing hafnium, e.g. HfO2}
- H10P 14/69433: {the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz}
- H10P 50/242: {of Group IV materials}
- H10P 50/283: {by chemical means}
- H10P 50/642: {Chemical etching}
- H10P 52/403: {of conductive or resistive materials}
- H10P 95/062: {involving a dielectric removal step}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method is presented for forming a wrap-around-contact. The method includes forming a bottom source/drain region adjacent a plurality of fins, disposing encapsulation layers over the plurality of fins, recessing at least one of the encapsulation layers to expose top portions of the plurality of fins, and for forming top spacers adjacent the top portions of the plurality of fins. The method further includes disposing a sacrificial liner adjacent the encapsulation layers, recessing the top spacers, forming top source/drain regions over the top portions of the plurality of fins, removing the sacrificial liner to create trenches adjacent the top source/drain regions, and depositing a metal liner within the trenches and over the top source/drain regions such that the wrap-around-contact is defined to cover an upper area of the top source/drain regions.

## Claims

### Claim 1

A method for forming a wrap-around-contact, the method comprising:
forming a bottom source/drain region adjacent a plurality of fins;
disposing encapsulation layers over the plurality of fins;
recessing at least one of the encapsulation layers to expose top portions of the plurality of fins;
forming top spacers adjacent the top portions of the plurality of fins;
disposing a sacrificial liner adjacent the encapsulation layers;
recessing the top spacers;
forming top source/drain regions over the top portions of the plurality of fins;
removing the sacrificial liner to create trenches adjacent the top source/drain regions; and
depositing a metal liner within the trenches and over the top source/drain regions such that the wrap-around-contact is defined to cover an upper area of the top source/drain regions.

### Claim 2 (depends on 1)

The method of claim 1, further comprising depositing a high-k layer and a work function metal (WFM) layer over the plurality of fins before disposing the encapsulation layers.

### Claim 3 (depends on 2)

The method of claim 2, further comprising forming a bottom spacer over the bottom source/drain region before deposition of the high-k layer and the WFM layer.

### Claim 4 (depends on 1)

The method of claim 1, wherein the wrap-around-contact defines a substantially inverted U-shaped configuration.

### Claim 5 (depends on 1)

The method of claim 1, wherein the encapsulation layers include a first encapsulation layer and a second encapsulation layer.

### Claim 6 (depends on 1)

The method of claim 1, wherein the recessing of the top spacers creates cavities underneath the sacrificial liner.

### Claim 7 (depends on 5)

The method of claim 5, wherein the top source/drain regions extend into the cavities formed underneath the sacrificial liner.

### Claim 8 (depends on 1)

The method of claim 1, wherein the metal liner is a thin silicide metal liner.

### Claim 9

A method for forming a wrap-around-contact, the method comprising:
forming a bottom source/drain region adjacent a plurality of fins;
depositing a high-k layer and a work function metal (WFM) layer over the plurality of fins;
disposing encapsulation layers over the WFM layer;
recessing the encapsulation layers to expose top portions of the plurality of fins;
forming top spacers adjacent the top portions of the plurality of fins;
disposing a sacrificial liner adjacent the encapsulation layers;
recessing the top spacers;
forming top source/drain regions over the top portions of the plurality of fins;
forming V-shaped grooves in the top source/drain regions;
removing the sacrificial liner to create trenches adjacent the top source/drain regions; and
depositing a metal liner within the trenches and over the V-shaped grooves of the top source/drain regions such that the wrap-around-contact is defined to cover an upper area of the top source/drain regions.

### Claim 10 (depends on 9)

The method of claim 9, further comprising forming a bottom spacer over the bottom source/drain region before deposition of the high-k layer and the WFM layer.

### Claim 11 (depends on 9)

The method of claim 9, wherein the wrap-around-contact defines a substantially M-shaped configuration.

### Claim 12 (depends on 9)

The method of claim 9, wherein the encapsulation layers include a first encapsulation layer and a second encapsulation layer.

### Claim 13 (depends on 9)

The method of claim 9, wherein the recessing of the top spacers creates cavities underneath the sacrificial liner.

### Claim 14 (depends on 13)

The method of claim 13, wherein the top source/drain regions extend into the cavities formed underneath the sacrificial liner.

### Claim 15 (depends on 9)

The method of claim 9, wherein the metal liner is a thin silicide metal liner.