Plasma processing method, plasma processing apparatus, and computer recording medium

• US 20050287725A1
• Filed: 08/05/2005
• Published: 12/29/2005
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Kitagawa, Junichi
• Granted Patent: US 7,807,234 B2
• Time in Patent Office: Days
• US Class Current: 438/161
• CPC Class Codes: A61P 31/04 Antibacterial agents
• CPC Class Codes: C23C 8/02 Pretreatment of the material to be coated C23C8/04 takes precedence
• CPC Class Codes: C23C 8/28 more than one element being applied in one step
• CPC Class Codes: C23C 8/34 more than one element being applied in more than one step
• CPC Class Codes: C23C 8/36 using ionised gases, e.g. ionitriding
• CPC Class Codes: C30B 33/005 Oxydation
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• 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 21/3144 on silicon

Abstract

According to the present invention, plasma oxidation processing and plasma nitridation processing are applied at the same time to the surface of a semiconductor substrate by plasma using a microwave. After forming an insulating film by the plasma oxynitridation processing as described above, the plasma nitridation processing is further applied to the insulating film as necessary. Thereby, it is possible to form the insulating film with an excellent electrical characteristic.

Claims

1. A plasma processing method applying processing to a substrate in a process vessel by using plasma, comprising the steps of:

introducing an inert gas, an oxygen gas, and a nitrogen gas into the process vessel;

making the gases into plasma by an antenna; and

forming an insulating film by applying oxidation processing and nitridation processing at the same time to a surface of the substrate by the plasma.

2. The plasma processing method according to claim 1, further comprising the step of making the inert gas and the nitrogen gas into plasma to apply the further nitridation processing to the insulating film, after forming the insulating film.

5. The plasma processing method according to claim 1,

wherein electron density of the plasma is 1.0×

10¹² (1/cm³) or more.

6. The plasma processing method according to claim 1,

wherein electron temperature of the plasma is 1.0 (eV) or less.

9. The plasma processing method according to claim 1,

wherein a flow rate ratio of the oxygen gas to the nitrogen gas is changed to control a peak of nitrogen concentration to a surface side and an interface of the insulating film.

11. The plasma processing method according to claim 9,

wherein the flow rate ratio of the oxygen to the nitrogen gas is 1:

4 to 1;

6.

13. The plasma processing method according to claim 9,

wherein the nitrogen concentration has the peak at a position closer to the interface than the surface of the insulating film.

14. The plasma processing method according to claim 9,

wherein the nitrogen concentration has the higher peak near the surface of the insulating film than the peak near the interface.

3. A plasma processing method forming an insulating film onto a substrate in a process vessel by using plasma, comprising the steps of:

supplying an inert gas, an oxygen gas, and a nitrogen gas into the process vessel;

supplying a microwave into the process vessel through an antenna to make the supplied gases into plasma by the microwave; and

forming the insulating film on the substrate by plasma processing of the inert gas, the oxygen gas, and the nitrogen gas.

4. The plasma processing method according to claim 3, further comprising the step of

supplying at least the inert gas and the nitrogen gas and making these gases into plasma by the microwave, after said step of forming the insulating film.

7. The plasma processing method according to claim 3,

wherein electron density of the plasma is 1.0×

10¹² (1/cm³) or more.

8. The plasma processing method according to claim 3,

wherein electron temperature of the plasma is 1.0 (eV) or less.

10. The plasma processing method according to claim 3,

wherein a flow rate ratio of the oxygen gas to the nitrogen gas is changed to control a peak of nitrogen concentration to a surface side and an interface of the insulating film.

12. The plasma processing method according to claim 10,

wherein the flow rate ratio of the oxygen to the nitrogen gas is 1:

4 to 1;

6.

15. The plasma processing method according to claim 10,

wherein the nitrogen concentration has the peak at a position closer to the interface than the surface of the insulating film.

16. The plasma processing method according to claim 10,

wherein the nitrogen concentration has the higher peak in proximity to the surface of the insulating film than the peak in proximity to the interface.

17. A plasma processing apparatus applying plasma processing to a substrate, comprising:

a process vessel containing the semiconductor substrate;

a microwave introducing portion introducing a microwave through an antenna and a dielectric which are provided to said process vessel; and

a gas supply portion supplying an inert gas, an oxygen gas, and a nitrogen gas to said process vessel,

wherein the inert gas, the oxygen gas, and the nitrogen gas are supplied by said gas supply portion into said process vessel, the microwave is introduced through said microwave introducing portion into said process vessel to make the gases into plasma, and oxidation processing and nitridation processing are applied at the same time to a surface of the substrate by the plasma to form an insulating film.

18. The plasma processing apparatus according to claim 17, wherein the antenna is a slot antenna.

19. The plasma processing apparatus according to claim 17, further comprising

a controller controlling a flow rate ratio of the oxygen gas to the nitrogen gas so that nitrogen concentration on a surface side of the insulating film and an interface side between the substrate and the insulating film are controlled.

20. The plasma processing apparatus according to claim 19, wherein the flow rate ratio of the oxygen gas to the nitrogen gas is 1:

4 to 1;

16.

21. A plasma processing method applying processing to a substrate in a process vessel by using plasma, comprising the steps of:

introducing an inert gas, an oxygen gas, and a nitrogen gas into the process vessel to form plasma of the inert gas, the oxygen gas, and the nitrogen gas; and

forming an insulating film on the substrate by applying oxidation processing and nitridation processing at the same time to a surface of the substrate by the plasma,

wherein electron temperature of the plasma is 1.0 (eV) or less.

22. The plasma processing method according to claim 21, further comprising the step of

applying the further nitridation processing to the insulating film, after said step of forming the insulating film.

23. The plasma processing method according to claim 21,

wherein the plasma is generated by a microwave introduced through a slot antenna.

24. The plasma processing method according to claim 21,

wherein a peak of nitrogen concentration in proximity to a surface of the insulating film and a peak of nitrogen concentration in proximity to an interface between the substrate and the insulating film are controlled by a flow rate ratio of the oxygen gas to the nitrogen gas.

25. The plasma processing method according to claim 21,

wherein the flow rate ratio of the oxygen gas to the nitrogen gas is 1:

4 to 1;

16.

26. The plasma processing method according to claim 24,

wherein the nitrogen concentration has the higher peak on an interface side than the peak on a surface side of the insulating film.

27. The plasma processing method according to claim 24,

wherein the nitrogen concentration has the higher peak in proximity to the surface side of the insulating film than the peak in proximity to the interface side.

28. The plasma processing method according to claim 21,

wherein the insulating film is SiON.

29. A computer recording medium containing software allowing a plasma processing apparatus to execute a plasma processing method,

wherein the plasma processing method comprises the steps of:

introducing an inert gas, an oxygen gas, and a nitrogen gas into a process vessel to form plasma of the inert gas, the oxygen gas, and the nitrogen gas; and

applying oxidation processing and nitridation processing at the same time to a surface of the substrate by the plasma to form an insulating film on the substrate,

wherein electron temperature of the plasma is 1.0 (eV) or less.