Method for forming composite gate dielectric layer equivalent to silicon oxide gate dielectric layer

• US 6,380,104 B1
• Filed: 08/10/2000
• Issued: 04/30/2002
• Est. Priority Date: 08/10/2000
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yu, Mo-Chiun
• Primary Examiner(s): Ghyka, Alexander G.
• Application Number:
  US09/636,582
• Time in Patent Office: 628 Days
• Field of Search: 438/775, 438/776, 438/777, 438/787
• US Class Current: 438/776
• 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 21/28211 in a gaseous ambient using an oxygen or a water vapour, e.g. RTO, possibly through a layer H01L21/28194 and H01L21/28202 take precedence
• 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
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material

Abstract

A method for forming upon a semiconductor substrate employed within a microelectronics fabrication a composite gate insulating layer of MOS device comprising a silicon oxide dielectric layer and a high-K dielectric layer. The method employs thermal oxidation of a silicon semiconductor substrate to form an initial silicon oxide dielectric layer. A RPN plasma method is employed to form a layer of silicon nitride high-k dielectric material partly into the silicon oxide dielectric layer. The composite dielectric layer is dielectrically equivalent to the initial silicon oxide dielectric layer, with equivalent performance, reliability and manufacturability of the MOS device.

Claims

1. A method for forming upon a semiconductor substrate employed within a microelectronics fabrication a composite dielectric layer comprising:

providing a silicon semiconductor substrate employed within a microelectronics fabrication;

thermally oxidizing said silicon semiconductor substrate to form a silicon oxide dielectric layer;

forming upon the surface of the silicon oxide dielectric layer a first layer of silicon nitride high-K dielectric material employing remote plasma nitridation (RPN) method such that the composite dielectric layer is dielectrically equivalent to the said initial silicon oxide dielectric layer; and

forming an optional additional layer of high-K dielectric material over the substrate.

2. The method of claim 1 wherein the thermal oxidation of said silicon semiconductor substrate employs a mixture of oxygen and nitrogen gases as the oxidizing atmosphere at a temperature range of from about 500 to about 800 degrees centigrade.

3. The method of claim 1 wherein the remote plasma nitridation (RPN) chemical vapor deposition (CVD) method employs microwave generation of a plasma in nitrogen gas to form active nitrogen radicals to convert part of the silicon oxide dielectric layer to silicon nitride high-K dielectric layer.

4. The method of claim 1 wherein the initial silicon oxide dielectric layer thickness is from about 5 to about 10 angstroms.

5. The method of claim 1 wherein the optional additional high-K dielectric material thickness is from about 20 to about 50 angstroms.

6. The method of claim 1 where the final remaining silicon oxide dielectric layer thickness is from zero to about 5 angstroms.

7. The method of claim 1 wherein said microelectronics fabrication is chosen from the group including but not limited to:

integrated circuit microelectronics fabrications;

charge coupled device microelectronics fabrications;

radiation emitting microelectronics fabrications; and

optoelectronics microelectronics fabrications.

8. A method for forming upon a silicon semiconductor substrate employed within an integrated circuit microelectronics fabrication a composite dielectric layer comprising

providing a silicon semiconductor substrate employed within an integrated circuit microelectronics fabrication;

forming upon said silicon substrate an initial silicon oxide dielectric layer;

forming upon the silicon substrate partly within the silicon oxide dielectric layer a first layer of silicon nitride high-K dielectric material such that the resulting composite dielectric layer is dielectrically equivalent to said initial silicon oxide dielectric layer; and

forming over the silicon semiconductor substrate an optional additional layer composed of silicon nitride high-K dielectric material.

9. The method of claim 8 wherein the initial silicon oxide dielectric layer is formed by the method of thermal oxidation employing a mixture of oxygen and nitrogen gases at a temperature of from about 500 to about 800 degrees centigrade in an oxidation apparatus.

10. The method of claim 8 wherein the initial silicon oxide dielectric layer thickness is from about 5 to about 10 angstroms.

11. The method of claim 8 a herein the first layer of silicon nitride high-KI dielectric material is formed employing remote plasma nitridation (RPN) chemical vapor deposition (CVD) method with microwave power.

12. The method of claim 11 wherein the first layer of silicon nitride high-K dielectric material is formed to a thickness of from about 10 to about 50 angstroms.

13. The method of claim 8 wherein the composite gate insulation layer of remaining silicon de dielectric material and silicon nitride high-K dielectric material is dielectrically equivalent to the initial silicon oxide dielectric layer.

14. The method of claim 8 wherein the composite gate insulation layer provides equivalent performance, reliability and manufacturability to the initial silicon oxide dielectric gate insulation layer.

15. The method of claim 8 wherein the optional additional layer of high-K material is chosen the group consisting of:

inorganic high-K dielectric materials; and

organic high-K dielectric materials.