Method of Fabricating a Gate Dielectric for High-K Metal Gate Devices

• US 20100075507A1
• Filed: 08/31/2009
• Published: 03/25/2010
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chang, Che-Hao, Yu, Chen-Hua, Wu, Tai-Bor, Hou, Cheng-Hao
• Granted Patent: US 9,711,373 B2
• Time in Patent Office: Days
• US Class Current: 438/763
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/308 Oxynitrides
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/02112 characterised by the material of the layer
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02227 formation by a process other than a deposition process
• CPC Class Codes: H01L 21/02236 group IV semiconductor
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02241 III-V semiconductor
• CPC Class Codes: H01L 21/02249 formation by combined oxidation and nitridation performed simultaneously
• CPC Class Codes: H01L 21/02252 formation by plasma treatment, e.g. plasma oxidation of the substrate after treatment of an insulating film by plasma H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 21/28202 : in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/306 : Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/31
• CPC Class Codes: H01L 21/30604 : Chemical etching
• CPC Class Codes: H01L 21/3141 : Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3145 : formed by deposition from a gas or vapour
• CPC Class Codes: H01L 21/31641 : Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 : Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 21/3185 : of siliconnitrides
• CPC Class Codes: H01L 29/513 : the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 : the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence

Abstract

The present disclosure provides a method of fabricating a semiconductor device. The method includes providing a substrate, forming an interfacial layer on the substrate by treating the substrate with radicals, and forming a high-k dielectric layer on the interfacial layer. The radicals are selected from the group consisting of hydrous radicals, nitrogen/hydrogen radicals, and sulfur/hydrogen radicals.

Claims

1. A method of fabricating a semiconductor device comprising:

providing a substrate;

forming an interfacial layer on the substrate by treating the substrate with radicals, wherein the radicals are selected from the group consisting of hydrous radicals, nitrogen/hydrogen radicals, and sulfur/hydrogen radicals; and

forming a high-k dielectric layer on the interfacial layer.

2. The method of claim 1, wherein the forming the interfacial layer includes generating the radicals by a plasma process or an ultraviolet (UV) process.

3. The method of claim 2, wherein the plasma process includes a temperature less than about 500 degree C., a total pressure ranging from 0.005 to about 10 Torr, a plasma power less than 200 W, and a time period less than about 1 minute.

4. The method of claim 2, wherein the UV process includes a temperature less than about 500 degree C., a total pressure ranging from 0.005 to about 10 Torr, a wavelength less than about 200 nm, and a time period less than about 1 minute.

5. The method of claim 1, wherein the radicals are generated from a gas selected from the group consisting of H₂O, H₂O₂, H₂, O₂, N₂, H₂S, (NH₄)₂S, NH₃, N₂H₂, N₂H₄, N₂, NO, N₂O, Ar, He, and combinations thereof.

6. The method of claim 5, wherein the hydrous radicals are generated with a H₂O/Ar gas mixture with a H₂O partial pressure less than about 0.1 Torr.

7. The method of claim 5, wherein the nitrogen/hydrogen radicals are generated with NH₃/Ar gas mixture with a NH₃ flow rate less than about 500 sccm.

8. The method of claim 5, wherein the sulfur/hydrogen radicals are generated with a H₂S/He gas mixture with a H₂S partial pressure less than 0.1 Torr.

9. The method of claim 1, wherein the forming the high-k dielectric layer is by atomic layer deposition (ALD) or metal-organic chemical vapor deposition (MOCVD).

10. The method of claim 1, wherein the forming the interfacial layer and the forming the high-k dielectric layer are performed in-situ.

11. The method of claim 1, wherein the substrate includes one of Si, Ge, Ga, As, In, Sb, and Al.

12. The method of claim 11, wherein the interfacial layer includes one of SiO₂, SiON, GeO₂, GeON, GaS_x, InS_x, AlS_x, and AsS_x.

13. A method of fabricating a semiconductor device comprising:

providing a substrate;

performing a first treatment on the substrate to form a first dielectric layer over the substrate, the first treatment including first radicals;

performing a second treatment on the first dielectric layer to form a second dielectric layer over the substrate, the second treatment including second radicals different from the first radicals, wherein the first and second radicals each includes one of hydrous radicals and nitrogen/hydrogen radicals; and

forming a high-k dielectric layer over the first and second dielectric layers.

14. The method of claim 13, wherein one of the first and second radicals is generated from a gas selected from the group consisting of NH₃, N₂H₂, N₂H₄, N₂, NO, N₂O, H₂O, H₂O₂, H₂, O₂, Ar, He, and combinations thereof.

15. The method of claim 13, wherein the first and second treatments each includes one of a plasma process and an ultraviolet (UV) process.

16. The method of claim 15, wherein the plasma process utilizes one of:

a H₂O/Ar gas mixture with a H₂O partial pressure less than about 0.1 Torr, an Ar flow rate ranging from 1000 to 200 sccm, a temperature less than about 500 degree C., a total pressure ranging from 0.005 to about 10 Torr, a plasma power less than 200 W, and a time period less than about 1 minute; and

a NH₃/Ar gas mixture with an NH₃ flow rate less than 500 sccm, an Ar flow rate ranging from 1000 to 200 sccm, a temperature less than 600 degree C., a total pressure ranging from 0.005 to about 10 Torr, a plasma power less than 3 kW, and a time period less than about 5 minutes.

17. The method of claim 15, wherein the UV process utilizes one of:

a H₂O/Ar gas mixture includes a H₂O partial pressure less than about 0.1 Torr, an Ar flow rate ranging from 1000 to 200 sccm, a temperature less than about 500 degree C., a total pressure ranging from 0.005 to about 10 Torr, a wavelength less than about 200 nm, and a time period less than about 1 minute; and

an NH₃/Ar gas mixture includes an NH₃ flow rate less than 500 sccm, Ar flow rate ranging from 1000 to 200 sccm, a temperature less than about 600 degree C., a total pressure ranging from 0.005 to about 10 Torr, a wavelength less than about 200 nm, and a time period less than about 5 minutes.

18. A method of fabricating a semiconductor device comprising:

providing a substrate;

forming an interfacial layer on the substrate including performing at least one treatment on the substrate, the at least one treatment including one of a plasma process and a UV process, the at least one treatment utilizing radicals selected from the group consisting of hydrous radicals, nitrogen/hydrogen radicals, and sulfur/hydrogen radicals; and

forming a high-k dielectric layer on the interfacial layer.

19. The method of claim 18, wherein the forming the interfacial layer includes:

performing a first treatment on the substrate to form a first dielectric layer over the substrate, the first treatment including first radicals; and

performing a second treatment on the first dielectric layer to form a second dielectric layer over the substrate, the second treatment including second radicals different from the first radicals.

20. The method of claim 18, wherein the forming the interfacial layer includes:

forming one of a SiO₂ layer and a SiON layer on a silicon (Si) substrate; and

performing the at least one treatment on one of the SiO₂ layer/Si substrate and SiON layer/Si substrate;

wherein an initial physical thickness of the one of the SiO₂ layer and SiON layer does not exceed 5 angstrom (Å

).