Method of forming high dielectric constant dielectric layer by atomic layer deposition

{
  "publication_number": "US10204788B1",
  "country": "US",
  "kind": "B1",
  "title": "Method of forming high dielectric constant dielectric layer by atomic layer deposition",
  "abstract": "A method of forming a high dielectric constant (high-k) dielectric layer by atomic layer deposition includes the following steps. Cycles are performed one after another, and each of the cycles sequentially includes performing a first oxygen precursor pulse to supply an oxygen precursor to a substrate disposed in a reactor; performing a first oxygen precursor purge after the first oxygen precursor pulse; performing a chemical precursor pulse to supply a chemical precursor to the substrate after the first oxygen precursor purge; and performing a chemical precursor purge after the chemical precursor pulse. The first oxygen precursor pulse, the first oxygen precursor purge, the chemical precursor pulse, and the chemical precursor purge are repeated by at least 3 cycles. A second oxygen precursor pulse is performed to supply an oxygen precursor to the substrate after the cycles. A second oxygen precursor purge is performed after the second oxygen precursor pulse.",
  "claims": [
    "1. A method of forming a high dielectric constant (high-k) dielectric layer by atomic layer deposition, comprising: performing a plurality of cycles one after another, each of the cycles sequentially comprising: (a) performing a first oxygen precursor pulse to supply an oxygen precursor to a substrate disposed in a reactor; (b) subsequent to step (a), performing a first oxygen precursor purge; (c) subsequent to step (b), performing a chemical precursor pulse to supply a chemical precursor to the substrate; and (d) subsequent to step (c), performing a chemical precursor purge, wherein steps (a) to (d) are repeated by at least 3 cycles; and performing a second oxygen precursor pulse to supply an oxygen precursor to the substrate after the cycles; and performing a second oxygen precursor purge after the second oxygen precursor pulse.",
    "2. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the second oxygen precursor pulse is different from the first oxygen precursor pulse in each of the cycles.",
    "3. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein a pulse duration of the second oxygen precursor pulse is longer than a pulse duration of the first oxygen precursor pulse in each of the cycles.",
    "4. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 3, wherein the pulse duration of the second oxygen precursor pulse is 3 to 10 times longer than the pulse duration of the first oxygen precursor pulse in each of the cycles.",
    "5. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein an oxygen precursor concentration of the second oxygen precursor pulse is higher than an oxygen precursor concentration of the first oxygen precursor pulse in each of the cycles.",
    "6. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the reactor is purged to remove the oxygen precursor by a purging gas in the first oxygen precursor purge.",
    "7. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the reactor is purged to remove the oxygen precursor by a purging gas in the second oxygen precursor purge.",
    "8. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein a purge duration of the second oxygen precursor purge is longer than a purge duration of the first oxygen precursor purge in each of the cycles.",
    "9. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the oxygen precursor of the first oxygen precursor pulse and the oxygen precursor of the second oxygen precursor pulse respectively comprise one selected from the group consisting H 2 O, O 2, O 3, and H 2 O 2.",
    "10. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the chemical precursor comprises a hafnium (Hf) precursor, a tantalum (Ta) precursor, or an aluminum (Al) precursor.",
    "11. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 10, wherein the Hf precursor comprises one selected from the group consisting HfCl 4 and tetrakis-ethyl methylaminohafnium (TEMAHf).",
    "12. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the second oxygen precursor pulse is the last pulse step in the atomic layer deposition.",
    "13. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the second oxygen precursor purge is the last step of the atomic layer deposition.",
    "14. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein there is not any chemical precursor pulse before the cycles in the atomic layer deposition.",
    "15. The method of forming the high-k dielectric layer by atomic layer deposition according to claim 1, wherein the first oxygen precursor pulse is the first step of the atomic layer deposition."
  ],
  "description_excerpt": "The present invention relates to a method of forming a high dielectric constant (high-k) dielectric layer, and more particularly, to a method of forming a high dielectric constant dielectric layer by atomic layer deposition (ALD).\n\nIn the continuously improved semiconductor integrated circuit technology, the sizes of the semiconductor devices become smaller for increasing the integrity of the integrated circuit. In the scaling down process, the thickness control of layers in the semiconductor device becomes more and more critical. As the thickness of the gate dielectric layer in the metal-oxide-semiconductor field effect transistor (MOSFET) decreases, leakage currents due to tunneling increase, leading to high power consumption and reduced device reliability. For improving the metal-oxide-semiconductor field effect transistor device performance as feature sizes continue to decrease, the traditional gate oxide and polysilicon gate electrode are replaced by a high dielectric constant (high-k) gate dielectric and a metal gate electrode. The high dielectric constant gate dielectric may be used to increase gate capacitance without the associated leakage effects. Defect states in the high dielectric constant gate dielectric can influence its electrical properties. Therefore, the material quality of the high dielectric constant gate dielectric is an important part for improving the performance and the reliability of the metal-oxide-semiconductor field effect transistor device\n\nA method of forming a high dielectric constant (high-k) dielectric layer by atomic layer deposition is provided in the present invention.",
  "cpc": [
    "H10D 64/01342",
    "C23C 16/405",
    "C23C 16/45527",
    "C23C 16/45553",
    "H01L 21/02178",
    "H01L 21/02181",
    "H01L 21/02183",
    "H01L 21/0228",
    "H01L 21/28194",
    "H01L 29/517",
    "H10D 64/691",
    "H10P 14/6339",
    "H10P 14/69391",
    "H10P 14/69392",
    "H10P 14/69393"
  ],
  "ipc": [
    "C23C 16/455",
    "H01L 21/02",
    "H10D 64/68"
  ],
  "assignees": [
    "United Microelectronics Corp"
  ],
  "inventors": [
    "Shan Ye",
    "Shih-Cheng Chen",
    "Tsuo-Wen Lu",
    "Tzu-Hsiang Su",
    "Po-Jen Chuang"
  ],
  "filing_date": "2018-01-01",
  "publication_date": "2019-02-12",
  "grant_date": "2019-02-12",
  "priority_date": "2018-01-01",
  "application_number": "US-201815859721-A",
  "family_id": "65241746",
  "cited_by_count": 344,
  "citations": [
    "US7067439B2",
    "US20040198069A1",
    "US7396719B2",
    "US20050239297A1",
    "US7727911B2",
    "US8288811B2"
  ]
}