SUBSTRATE PROCESSING METHOD

• US 20110204025A1
• Filed: 05/02/2011
• Published: 08/25/2011
• Est. Priority Date: 08/15/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: TAHARA, Shigeru
• Granted Patent: US 8,492,287 B2
• Time in Patent Office: Days
• US Class Current: 216/37
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/67201 characterized by the construction of the load-lock chamber
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence

Abstract

A silicon-containing film on a substrate is subjected to a plasma process using a process gas containing fluorine and carbon, and is thereafter subjected to plasma process using an ammonia gas, whereby ammonium silicofluoride having toxicity and hygroscopic property is adhered to the substrate. The harmful ammonium silicofluoride is removed by the inventive method. After conducting the plasma process using an ammonia gas, the substrate is heated to a temperature not lower than the decomposition temperature of the ammonium silicofluoride to decompose the ammonium silicofluoride in a process container in which the plasma process was conducted, or in a process container connected with the processing vessel which the plasma process was conducted therein and is isolated from a clean room atmosphere.

Claims

1-14. -14. (canceled)

15. A substrate processing method comprising:

(a) placing a substrate in a processing vessel, the substrate having thereon a stacked film structure, the structure including a wiring layer, an etch stop film formed on the wiring layer, an interlayer insulating film formed over the etch stop film and a photoresist mask formed over the interlayer insulating film;

(b) dry-etching the stacked film structure down to the etch stop layer using the photoresist mask as an etch mask in the processing vessel, thereby forming a recess in the interlayer insulating film;

(c) supplying a gas containing carbon and fluorine in a processing vessel, generating a plasma from the gas, and etching the etch stop layer down to the wiring layer by the plasma, the etching of the etch stop layer by the plasma resulting in a situation where CF series polymer is deposited on the wiring layer; and

(d) supplying a gas containing nitrogen and hydrogen in a processing vessel, generating a plasma from the gas, and applying the plasma to the substrate, thereby removing the CF series polymer, the applying of the plasma to the CF series polymer resulting in a situation where the CF series polymer is dissociated to forms fluorine, and the fluorine, together with silicon, nitrogen and hydrogen, form a compound containing fluorine, silicon, nitrogen and hydrogen; and

(e) heating the substrate at a temperature not less than 100°

C. and not less than decomposition temperature of the compound, thereby decomposing the compound and removing the compound from the substrate.

16. The substrate processing method according to claim 15, wherein step (a) to step (d) are performed in one processing vessel, and step (e) is performed in another processing vessel after the substrate is transferred from said one processing vessel to said another processing vessel through a vacuum transfer space.

17. The substrate processing method according to claim 15, wherein the gas containing nitrogen and hydrogen is ammonia gas or a hydrazine series gas.

18. The substrate processing method according to claim 15, wherein the compound containing fluorine, silicon, nitrogen and hydrogen is ammonium silicofluoride.

19. The substrate processing method according to claim 15, wherein the gas containing carbon and fluorine is CF₄ gas or C₂F₆ gas.

20. The substrate processing method according to claim 15, wherein the stacked film structure further includes an organic film and a SiO₂ film.

21. The substrate processing method according to claim 15, wherein the etch stop film is a SiC film or a SiCN film.

22. A substrate processing method comprising:

(a) providing a substrate having thereon a stacked film structure, the structure including a wiring layer, an etch stop film formed on the wiring layer, an interlayer insulating film formed over the etch stop film and a photoresist mask formed over the interlayer insulating film;

(b) dry-etching the stacked film structure down to the etch stop layer using the photoresist mask as an etch mask, thereby forming a first recess in the interlayer insulating film;

(c) etching the etch stop layer down to the wiring layer using a plasma of a gas containing carbon and fluorine, thereby forming a second recess in the etch stop layer, the etching of the etch stop layer by the plasma resulting in a situation where a CF series polymer is deposited on the wiring layer; and

(d) applying a plasma of a gas containing nitrogen and hydrogen to the substrate, thereby removing the CF series polymer, the applying of the plasma resulting in a situation where the CF series polymer is dissociated to form fluorine, and the fluorine, together with silicon, nitrogen and hydrogen, forms a compound containing fluorine, silicon, nitrogen and hydrogen;

(e) heating the substrate at a temperature not less than 100°

C. and not less than decomposition temperature of the compound, thereby decomposing the compound and removing the compound from the substrate;

(f) etching the interlayer insulating film to form a trench above the first and the second recesses; and

(g) embedding the trench and the first and the second recesses with a wiring material.

23. The substrate processing method according to claim 22, wherein the gas containing nitrogen and hydrogen is ammonia gas or a hydrazine series gas.

24. The substrate processing method according to claim 22, wherein the compound containing fluorine, silicon, nitrogen and hydrogen is ammonium silicofluoride.

25. The substrate processing method according to claim 22, wherein the gas containing carbon and fluorine is CF₄ gas or C₂F₆ gas.

26. The substrate processing method according to claim 22, wherein the stacked film structure further includes an organic film and a SiO₂ film.

27. The substrate processing method according to claim 22, wherein the etch stop film is a SiC film or a SiCN film.