Hydrogen assisted HDP-CVD deposition process for aggressive gap-fill technology

• US 6,808,748 B2
• Filed: 01/23/2003
• Issued: 10/26/2004
• Est. Priority Date: 01/23/2003
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wang, Anchuan, Karim, M. Ziaul, Kapoor, Bikram
• Primary Examiner(s): MEEKS, TIMOTHY HOWARD
• Application Number:
  US10/350,445
• Publication Number:
  US 20040146661A1
• Time in Patent Office: 642 Days
• Field of Search: 427/255.31, 427/255.37, 427/255.38, 427/575, 438/695
• US Class Current: 427/255.31
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• 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 21/31612 on a silicon body

Abstract

A method of depositing a silicon oxide layer over a substrate having a trench formed between adjacent raised surfaces. In one embodiment the silicon oxide layer is formed in a multistep process that includes depositing a first portion of layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and helium and/or molecular hydrogen with high D/S ratio, for example, 10-20 and, thereafter, depositing a second portion of the silicon oxide layer over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and molecular hydrogen with a lower D/S ratio of, for example, 3-10.

Claims

1. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising, in order:

depositing a first portion of the silica glass film over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and helium, but substantially no molecular hydrogen; and

thereafter, depositing a second portion of the silica glass film over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and molecular hydrogen.

2. The method of claim 1 wherein the silicon source in the first and second process gases comprises monosilane (SiH₄).

3. The method of claim 2 wherein the oxygen source in the first and second process gases comprises molecular oxygen (O₂).

4. The method of claim 1 wherein the first portion of the silica glass film reduces a height of the trench by between 30-65 percent.

5. The method of claim 4 wherein the second portion of the silica glass film completes the filling of the trench.

6. The method of claim 1 wherein the first process gas consists of SiH4, O2 and helium and the second process gas consists of SiH₄, O₂ and molecular hydrogen.

7. The method of claim 6 wherein ratio of the flow rate of helium to molecular hydrogen is varied over time in a step-wise manner.

8. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising, in order:

depositing a first portion of the silica glass film over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and molecular hydrogen, wherein the first portion of the silica glass film is deposited at a first D/S ratio; and

thereafter, depositing a second portion of the silica glass film over the first portion as deposited and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and, wherein the second portion of the silica glass layer is deposited at a second D/S ratio less than the first ratio.

9. The method of claim 8 wherein the silicon source in the first and second process gases comprises monosilane (SiH₄).

10. The method of claim 9 wherein the oxygen source in the first and second process gases comprises molecular oxygen (O₂).

11. The method of claim 8 wherein the first portion of the silica glass film reduces a height of the trench by between 10-50 percent.

12. The method of claim 11 wherein the second portion of the silica glass film completes the filling of the trench.

13. The method of claim 8 wherein the first process gas consists of SiH₄, O₂ and hydrogen and the second process gas consists of SiH₄, O₂ and hydrogen.

14. The method of claim 8 wherein the first D/S ratio is between 10 and 20 and the second D/S ratio is between 3 and 10.

15. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising, in order:

depositing a first portion of the silica glass film over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a first process gas comprising a silicon source, an oxygen source and a first fluent gas; and

thereafter, depositing a second portion of the silica glass film over the substrate and within the trench by forming a high density plasma process that has simultaneous deposition and sputtering components from a second process gas comprising a silicon source, an oxygen source and a second fluent gas, wherein an average molecular mass of the second fluent gas is less than an average molecular mass of the first fluent gas.

16. A method of depositing a silica glass film on a substrate disposed in a substrate processing chamber, the substrate having a trench formed between adjacent raised surfaces, the method comprising:

flowing a process gas comprising a silicon source, an oxygen source, helium and molecular hydrogen into the chamber; and

forming a plasma having an ion density of at least 1×

10¹¹ ions/cm³ from said process gas to deposit said silicon oxide layer over said substrate in a process that has simultaneous deposition and sputtering components;

wherein during deposition of the silicon oxide layer a ratio of a flow rate of helium to molecular hydrogen is decreased.

17. The method of claim 16 wherein the silicon source comprises monosilane (SiH₄).

18. The method of claim 17 wherein the oxygen source comprises molecular oxygen (O₂).

19. The method of claim 17 wherein the process gas further comprises argon.

20. The method of claim 17 wherein at an initial stage of deposition of the silicon oxide layer the process gas consists of SiH₄, O₂ and helium and, during a subsequent stage of deposition of the silicon oxide layer, the process gas consists of SiH₄, O₂, helium and molecular hydrogen.

21. The method of claim 20 wherein during a final stage of deposition of the silicon oxide layer the process gas consists of SiH₄, O₂ and molecular hydrogen.