High throughput chemical vapor deposition process capable of filling high aspect ratio structures

{
  "publication_number": "US6030881A",
  "country": "US",
  "kind": "A",
  "title": "High throughput chemical vapor deposition process capable of filling high aspect ratio structures",
  "abstract": "A method is provided for filling high aspect ratio gaps without void formation by using a high density plasma (HDP) deposition process with a sequence of deposition and etch steps having varying etch rate-to-deposition rate (etch/dep) ratios. The first step uses an etch/dep ratio less than one to quickly fill the gap. The first step is interrupted before the opening to the gap is closed. The second step uses an etch/dep ratio greater than one to widen the gap. The second step is stopped before corners of the elements forming the gaps are exposed. These steps can be repeated until the aspect ratio of the gap is reduced so that void-free gap-fill is possible. The etch/dep ratio and duration of each step can be optimized for high throughput and high aspect ratio gap-fill capacity.",
  "claims": [
    "1. A process, in integrated circuit production, for filling a gap having an opening of initial width in the surface of a substrate, comprising the steps of: first depositing a film in said gap using an HDP CVD process having an etch/dep ratio greater than about 0.02; stopping said first depositing before said opening closes; etching said film in said gap; stopping said etching before corners of elements forming said gap are exposed; and later depositing a film in said gap.",
    "2. The process of claim 1, wherein said step of first depositing is stopped when said opening is no less than about 40% of said initial width.",
    "3. The process of claim 1, wherein said etch/dep ratio of said step of depositing is less than or equal to approximately 0.25.",
    "4. The process of claim 1, wherein said step of depositing is performed with a gas mixture comprising oxygen, silane, and an inert gas.",
    "5. The process of claim 4, wherein said inert gas for said step of depositing is argon, neon, or helium.",
    "6. The process of claim 1, further comprising repeating one or more cycles of said step of first depositing and said step of etching until said gap is filled without leaving a void in said gap.",
    "7. The process of claim 1 wherein said film is undoped silica glass.",
    "8. The process of claim 1 wherein said film is doped silica glass.",
    "9. The process of claim 8 wherein said step of first depositing is performed with a dopant gas comprising a gas selected from the group consisting of phosphine (PH 3), diborane (B 2 H 6), and arsine (AsH 3).",
    "10. The process of claim 1, wherein said substrate is attached to and heated or cooled by a thermally controllable electrostatic chuck.",
    "11. The process of claim 10 wherein said electrostatic chuck is resistively heated.",
    "12. The process of claim 10 wherein said substrate attached to said electrostatic chuck is cooled with backside flow of helium.",
    "13. The process of claim 1 wherein said step of etching is performed simultaneously with a second deposition, such that said step of etching is performed with an etch/dep ratio of greater than one.",
    "14. The process of claim 13 wherein said step of etching is performed with an etch/dep ratio greater than about 50.",
    "15. The process of claim 1 wherein said step of etching is performed by sputter etching.",
    "16. The process of claim 1 wherein said step of etching is performed by a non-fully directional etching process.",
    "17. The process of claim 1 wherein said step of etching is performed with a gas mixture comprising an inert gas having an atomic weight lower than that of argon.",
    "18. The process of claim 17 wherein said gas mixture for said step of etching further comprises a reactive etch gas.",
    "19. The process of claim 17 wherein said gas mixture for said step of etching further comprises oxygen.",
    "20. The process of claim 17 wherein said gas mixture for said step of etching further comprises silane.",
    "21. The process of claim 20 wherein said step of depositing is performed with a gas mixture comprising an inert gas, oxygen, and silane.",
    "22. The process of claim 1 wherein said step of etching is performed in situ.",
    "23. The process of claim 1 wherein said step of first depositing and said step of etching are performed in a single process chamber.",
    "24. A process, in integrated circuit production, for depositing an oxide film to fill a gap having an opening of initial width in the surface of a substrate of a less than or equal to about 0.15 microns and a depth, wherein the ratio of said depth to said initial width defines a high aspect ratio of about 5:1 or greater, said process comprising the steps of: first depositing an oxide film in said gap using an HDP CVD process having an etch/dep ratio between about 0.02 and about 0.25; stopping said first depositing when said opening is narrowed to no less than about 40% of said initial width; etching, in situ, said oxide film in said gap with an HDP etching process; stopping said etching before corners of elements forming said gap are exposed; and later depositing an oxide film in said gap.",
    "25. The process of claim 24 wherein said step of etching is performed with a gas mixture comprising an inert gas having an atomic weight lower than that of argon.",
    "26. The process of claim 24 wherein said step of etching is performed with a reactive etch gas.",
    "27. The process of claim 26 wherein said gas mixture for said step of etching comprises oxygen.",
    "28. The process of claim 24 wherein said step of depositing is performed with a dopant gas comprising a gas selected from the group consisting of phosphine (PH 3), diborane (B 2 H 6), and arsine (AsH 3).",
    "29. The process of claim 24 wherein said step of etching is performed simultaneously with a second deposition such that said step of etching is performed with an etch/dep ratio greater than about 50.",
    "30. The process of claim 24 wherein said step of etching is performed by sputter etching.",
    "31. The process of claim 24 wherein said step of etching is performed with a non-fully directional etch process.",
    "32. The process of claim 24 wherein said gas mixture for said step of etching further comprises silane.",
    "33. The process of claim 32 wherein said depositing is performed with a gas mixture comprising an inert gas, oxygen, and silane.",
    "34. The process of claim 24 wherein said step of first depositing and said step of etching are performed in a single process chamber."
  ],
  "cpc": [
    "H10W 10/014",
    "C23C 16/045",
    "C23C 16/401",
    "C23C 16/56",
    "H10W 10/17"
  ],
  "assignees": [
    "NOVELLUS SYSTEMS INC",
    "IBM"
  ],
  "filing_date": "1998-05-05",
  "publication_date": "2000-02-29",
  "grant_date": "2000-02-29",
  "priority_date": "1998-05-05",
  "application_number": "US-7275998-A",
  "family_id": "22109576",
  "citations": [
    "US5270264A",
    "US5494854A",
    "US5621241A",
    "US5872058A",
    "US5920792A",
    "US5937323A"
  ]
}