Barrier layer deposition using HDP-CVD

• US 6,399,489 B1
• Filed: 11/01/1999
• Issued: 06/04/2002
• Est. Priority Date: 11/01/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: MʼSaad, Hichem, Cho, Seon Mee, Tribula, Dana
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): YEVSIKOV, VICTOR V
• Application Number:
  US09/431,411
• Time in Patent Office: 946 Days
• Field of Search: 438/680, 438/758, 438/761, 438/778, 438/792, 438/793, 438/479, 438/931
• US Class Current: 438/680
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: H01L 21/02131 the material being halogen doped silicon oxides, e.g. FSG
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/314 Inorganic layers H01L21/3105, H01L21/32 take precedence
• CPC Class Codes: H01L 21/3146 Carbon layers, e.g. diamond-like layers
• CPC Class Codes: Y10S 438/931 Silicon carbide semiconductor

Abstract

A method of depositing a film, such as a barrier layer, on a substrate using a gaseous mixture including a hydrocarbon-containing gas and a silicon-containing gas. Suitable hydrocarbon-containing gases include alkanes such as methane (CH₄), ethane (C₂H₆), butane (C₃H₈), propane (C₄H₁₀), etc. Suitable silicon-containing gases include silanes such as monosilane (SiH₄). The method generally comprises providing a suitable gaseous mixture to the chamber, generating a plasma from the gaseous mixture, and depositing a film onto the substrate using the plasma. In a preferred embodiment, the film is deposited in a high-density plasma chemical vapor deposition (HDP-CVD) system. The gaseous mixture typically includes a silicon containing gas, such as an alkane, and a hydrocarbon containing gas, such as a silane. Embodiments of the method of the present invention can integrated stack structures having overall dielectric constant of about 4.0 or less. Such a structure may include a barrier layer having a dielectric constant of 4.5 or less.

Claims

1. A method for depositing a barrier layer over a substrate disposed in a process chamber, the method comprising:

(a) flowing a gaseous mixture comprising a silicon containing gas, and a hydrocarbon containing gas to the chamber, wherein the gaseous mixture has a carbon;

silicon ratio less than 8;

1 and greater than 1;

1;

(b) generating a plasma from said gaseous mixture; and

(c) depositing the barrier layer over the substrate with a dielectric layer to form an intermetal dielectric layer in a damascene structure,

wherein the barrier layer includes silicon (Si), carbon (C), and hydrogen (H), and said hydrogen is incorporated into the barrier layer in a concentration of about 50 atomic percent or less.

2. The method of claim 1 wherein said plasma is a high-density plasma.

3. The method of claim 1 wherein said silicon containing gas includes a silane.

4. The method of claim 3 wherein said silane is monosilane (SiH₄), disilane (Si₂H₆), trisilane (Si₃H₈), or tetrasilane (Si₄H₁₀).

5. The method of claim 1 wherein said hydrocarbon containing gas includes an alkane.

6. The method of claim 3 wherein said alkane is methane, ethane, butane, propane, pentane or hexane.

7. The method of claim 1 wherein the gaseous mixture consists essentially of one or more hydrocarbon gases, a silicon containing gas and an inert gas.

8. The method of claim 1 wherein said carbon:

silicon ratio is between about 3;

1 and about 8;

1.

9. The method of claim 1 wherein said carbon and said silicon are incorporated into the barrier layer in a C/Si atomic ratio of between about 55/45 and about 65/35.

10. The method of claim 1 wherein said barrier layer has a dielectric constant of about 4.5 or less.

11. The method of claim 1 wherein said barrier layer has a thickness of between about 500 Å

and 1000 Å

.

12. The method of claim 1 wherein said barrier layer is deposited on the dielectric layer on the substrate, said dielectric layer having a dielectric constant of about 3.5 or less.

13. The method of claim 1 further comprising, depositing the dielectric layer of material over said barrier layer, said dielectric layer having a dielectric constant of about 3.5 or less.

14. The method recited in claim 1 wherein the dielectric layer comprises a fluorinated silicate glass layer.

15. A method for depositing a barrier layer on a substrate in a process chamber, comprising:

(a) flowing a gaseous mixture containing flows of silane (SiH₄) and methane (CH₄) into the chamber, wherein said flows of silane and methane have a methane;

silane flow rate ratio less than 8;

1 and greater than 1;

1;

(b) generating a high-density plasma from said gaseous mixture; and

(c) depositing the barrier layer with a dielectric layer onto the substrate using said plasma,

wherein the barrier layer includes silicon (Si), carbon (C), and hydrogen (H), and said hydrogen is incorporated into barrier layer in a concentration of about 50 atomic percent or less.

16. The method of claim 15 wherein said methane:

silane flow rate ratio is between about 3;

1 and 8;

1.

17. The method of claim 16 wherein said gaseous mixture further includes a flow of argon (Ar).

18. The method of claim 15 wherein said barrier layer has a dielectric constant of about 4.5 or less.

19. The method recited in claim 15 wherein the dielectric layer comprises a fluorinated silicate glass layer.

20. A computer readable storage medium having a computer-readable program embodied therein for directing operation of a substrate processing system including a process chamber;

a plasma generation system;

a substrate holder;

a gas delivery system configured to introduce gases into the process chamber, the computer-readable program including instructions for operating the substrate processing system to form a substrate disposed in the processing chamber in accordance with the following;

(a) flowing a gaseous mixture containing flows of a silicon containing gas, and a hydrocarbon containing gas into the chamber, wherein the gaseous mixture has a carbon;

silicon ratio less than 8;

1 and greater than 1;

1;

(b) generating a plasma from said gaseous mixture; and

(c) depositing the barrier layer over the substrate with a dielectric layer to form an intermetal dielectric layer in a damascene structure;

wherein the barrier layer includes silicon (Si), carbon (C), and hydrogen (H), and said hydrogen is incorporated into the barrier layer in a concentration of about 50 atomic percent or less.

21. A substrate processing system comprising:

a housing defining a process chamber;

a plasma generating system coupled to said processing chamber;

a substrate holder, configured to hold a substrate during substrate processing;

a gas delivery system configured to introduce gases into said process chamber;

a controller for controlling said gas delivery system and said plasma generating system; and

a memory coupled to said controller comprising a computer-readable medium having a computer-readable program embodied therein for directing operation of said substrate processing system, said computer-readable program including

(a) a first set of instructions directing said gas delivery system to flow a gaseous mixture containing flows of a silicon containing gas, and a hydrocarbon containing gas into the process chamber, wherein the gaseous mixture has a carbon;

silicon ratio less than 8;

1 and greater than 1;

1; and

(b) a second set of instructions directing the plasma generating system to generate a plasma from said gaseous mixture to deposit the barrier layer over the substrate with a dielectric layer to form an intermetal dielectric layer in a damascene structure,

wherein the barrier layer includes silicon (Si), carbon (C), and hydrogen (H), and said hydrogen is incorporated into the barrier layer in a concentration of about 50 atomic percent or less.

22. A method for depositing a barrier layer over a substrate disposed in a process chamber, the method comprising:

(a) flowing a gaseous mixture consisting essentially of a silicon containing gas and a hydrocarbon containing gas to the chamber, wherein the gaseous mixture has a carbon;

silicon ratio less than 8;

1 and greater than 1;

1; and

(b) generating a plasma from said gaseous mixture and using said plasma to deposit the barrier layer over the substrate with a dielectric layer to form an intermetal dielectric layer in a damascene structure,

wherein the barrier layer includes silicon (Si), carbon (C), and hydrogen (H), and said hydrogen is incorporated into the baffler layer in a concentration of about 50 atomic percent or less.

23. The method of claim 22 wherein said carbon and said silicon are incorporated into the barrier layer in a C/Si atomic ratio of between about 55/45 and about 65/35.

24. The method of claim 22 wherein said hydrogen is incorporated into the barrier layer in a concentration of about 50 atomic percent or less.

25. The method recited in claim 22 wherein the dielectric layer comprises a fluorinated silicate glass layer.