Method for forming silicon-containing dielectric film by cyclic deposition with side wall coverage control

• US 8,722,546 B2
• Filed: 06/11/2012
• Issued: 05/13/2014
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Fukazawa, Atsuki, Oka, Takahiro
• Primary Examiner(s): Nikmanesh, Seahvosh
• Assistant Examiner(s): Seven, Evren
• Application Number:
  US13/493,897
• Publication Number:
  US 20130330933A1
• Time in Patent Office: 701 Days
• Field of Search: 438/778
• US Class Current: 438/778
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• 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 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz 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 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD

Abstract

A method of forming a dielectric film having Si—C bonds and/or Si—N bonds on a semiconductor substrate by cyclic deposition, includes: (i) conducting one or more cycles of cyclic deposition in a reaction space wherein a semiconductor substrate is placed, using a Si-containing precursor and a reactant gas; and (ii) before or after step (i), applying a pulse of RF power to the reaction space while supplying a rare gas and a treatment gas without supplying a Si-containing precursor, whereby a dielectric film having Si—C bonds and/or Si—N bonds is formed on the semiconductor substrate.

Claims

1. A method of forming a dielectric film having Si—

C bonds and/or Si—

N bonds on a semiconductor substrate by cyclic deposition, which comprises;

(i) conducting one or more cycles of cyclic deposition in a reaction space w herein a semiconductor substrate is placed, each cycle having a period supplying a Si-containing precursor and a reactant gas simultaneously, without RF power, and a period applying a pulse of RF power to the reaction space while supplying the reactant gas; and

(ii) before or after step (i), but not during step (i), applying a pulse of RF power to the reaction space while supplying a rare gas and a treatment gas without supplying the Si-containing precursor,

whereby a dielectric film having Si—

C bonds, Si—

N bonds, or Si—

C and Si—

N bonds is formed on the semiconductor substrate.

2. The method according to claim 1, wherein steps (i) and (ii) are repeated alternately to for the dielectric film.

3. The method according to claim 1, wherein the treatment gas in step (ii) is at least one gas selected from the group consisting of N-containing gases, H-containing gases, and C-containing gases.

4. The method according to claim 3, Wherein the treatment gas is at least one gas selected from the group consisting of N₂, NH₃, N_xH_y, C_aH_b, C_aH_bN_c, and H₂ wherein x, y, z, a, b, and c are integers.

5. The method according to claim 1, wherein in step (ii), the total flow rate of the rare gas and the treatment gas is 100 sccm to 5,000 sccm, and the temperature of the substrate is 50°

C. to 650°

C.

6. The method according to claim 1, wherein a ratio of the treatment gas flow to the rare gas flow is 0.001/1 to 10/1.

7. The method according to claim 1, wherein the duration of step (i) is T1, and the duration of step (ii) is T2, wherein T2/T1 is 0.01 to 0.1.

8. The method according to claim 1, wherein the cyclic deposition is atomic layer deposition (ALD).

9. The method according to claim 8, wherein the ALD is plasma-enhanced ALD, thermal ALD, or radical-enhanced ALD.

10. The method according to claim 8, wherein step (ii) is conducted before step (i).

11. The method according to claim 1, wherein the cyclic deposition is plasma enhanced CVD.

12. The method according to claim 11, wherein step (ii) is conducted after step (i).

13. The method according to claim 11, wherein the Si-containing precursor contains silicon, halogen, and hydrocarbon in its molecule.

14. The method according to claim 1, wherein the treatment gas and the reactant gas are the same gas.

15. The method according to claim 1, wherein steps (i) and (ii) are conducted continuously in sequence.

16. The method according to claim 1, wherein the semiconductor substrate has patterned recesses on which the dielectric film is formed, each patterned recess including a top surface, side wall, and bottom surface.

17. The method according to claim 16, wherein the dielectric film has a side wall coverage of over 85%, which is defined as a ratio of thickness of film deposited on the side wall to thickness of film deposited on the top surface.

18. The method according to claim 1, wherein the number of times steps (i) and (ii) are conducted is M, the number of cycles the cyclic deposition is conducted in step (i) is N, and M·

N is constant and determined in order to obtain a target thickness of the dielectric film, wherein N is 1 to 30,000.

20. The method according to claim 1, wherein the dielectric film is constituted by SiC or SiN.

19. A method of forming, a dielectric film having Si—

C bonds and/or Si—

N bonds on a semiconductor substrate by cyclic deposition, which comprises;

(i) conducting one or more cycles of cyclic deposition in a reaction space wherein a semiconductor substrate is placed, using a Si-containing precursor and a reactant gas; and

(ii) before or after step (i), applying a pulse of RF power to the reaction space while supplying a rare gas and a treatment gas without supplying the Si-containing precursor,

whereby a dielectric film having Si—

C bonds, Si—

N bonds, or Si—

C and Si—

N bonds is formed on the semiconductor substrate,

wherein the semiconductor substrate has patterned recesses on which the dielectric film is formed, each patterned recess including a top surface, side wall, and bottom surface, and the dielectric film is formed as a first dielectric film wherein the duration of step (i) is T1, and the duration of step (ii) is T2, said method further comprising;

determining a side wall coverage of the first dielectric film as a first side wall coverage, which side wall coverage is defined as a ratio of thickness of film deposited on the side wall to thickness of film deposited on the top surface; and

conduct steps (i) and (ii) to form a second dielectric film having a second side wall coverage on a substrate using T2/T1 which is higher than T2/T1 used for the first dielectric film so as to render the second side wall coverage higher than the first side wall coverage, said second side wall coverage being over 85%.