Method for forming film having low resistance and shallow junction depth

• US 9,478,415 B2
• Filed: 02/13/2015
• Issued: 10/25/2016
• Est. Priority Date: 02/13/2015
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Kimura, Yosuke, de Roest, David
• Primary Examiner(s): Karimy, Timor
• Application Number:
  US14/622,603
• Publication Number:
  US 20160240367A1
• Time in Patent Office: 620 Days
• Field of Search: 438/763, 438/758
• US Class Current: 1/1
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45538 Plasma being used continuously during the ALD cycle
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• 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 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD

Abstract

A method for forming on a substrate a doped silicon oxide film with a cap film, includes: forming an arsenosilicate glass (ASG) film as an arsenic (As)-doped silicon oxide film on a substrate; continuously treating a surface of the ASG film with a treating gas constituted by Si, N, and H without excitation; and continuously forming a silicon nitride (SiN) film as a cap film on the treated surface of the ASG film.

Claims

1. A method for forming on a substrate a doped silicon oxide film with a cap film, comprising:

(i) forming an arsenosilicate glass (ASG) film having a desired thickness as an arsenic (As)-doped silicon oxide film on a substrate;

(ii) after completion of step (i), continuously treating a surface of the ASG film with a treating gas constituted by Si, N, and H without excitation of the treating gas so as to adsorb the treating gas on the surface of the ASG film; and

(iii) after completion of step (ii), continuously forming a silicon nitride (SiN) film as a cap film on the treating gas-adsorbed surface of the ASG film.

2. The method according to claim 1, wherein all the gases including the treating gas used in step (ii) are identical to all the gases used in step (iii).

3. The method according to claim 1 wherein in step (ii), the treating gas is supplied with a noble gas.

4. The method according to claim 1, wherein the treating gas comprises N₂ gas, SiH₄ gas, and H₂ gas.

5. The method according to claim 1, wherein step (ii) is conducted at a temperature of 100°

C. to 300°

C.

6. The method according to claim 1, wherein the concentration of As in the ASG film is approximately 1E+22 atom/cm³.

7. The method according to claim 1, wherein the thickness of the ASG film formed in step (i) is approximately 5 nm or less.

8. The method according to claim 1, wherein in step (i), the ASG film is formed by atomic layer deposition (ALD) with solid-state doping.

9. The method according to claim 8, wherein the solid-state doping is conducted at a temperature of approximately 300°

C. or lower.

10. The method according to claim 8, wherein the ALD is a plasma-enhanced ALD.

11. The method according to claim 1, wherein the thickness of the SiN film formed in step (iii) is approximately 5 nm or less.

12. The method according to claim 1, wherein the substrate is a silicon wafer.

13. The method according to claim 1, wherein the SiN film is deposited by cyclic CVD.

14. The method according to claim 13, wherein the cyclic CVD comprises feeding a precursor for the SiN film in pulses to a reaction space while maintaining pressure of the reaction space.

15. The method according to claim 1, further comprising, after step (iii), annealing the SiN film formed on the ASG film.

16. The method according to claim 15, wherein a sheet resistance (Rs) and an As-junction depth (Xj) of 5E+18 atom/cm³ at an interface between the ASG film and the substrate after the annealing step are approximately 500 ohm/sq or less, and approximately 5 nm or less, respectively.

17. The method according to claim 15, wherein the in-film concentration of As in the ASG film is approximately 1E+22 atom/cm³.

18. The method according to claim 1, wherein steps (i) to (iii) are conducted in a same reaction chamber.