Production of semiconductor integrated circuit

{
  "publication_number": "US6740901B2",
  "country": "US",
  "kind": "B2",
  "title": "Production of semiconductor integrated circuit",
  "abstract": "A semiconductor integrated circuit in which the storage capacitor has an increased capacitance and a decreased leakage current. The storage capacitor is formed by the steps of: forming a polysilicon bottom electrode having semispherical silicon crystals formed thereon; performing plasma nitriding on the surface of said bottom electrode at a temperature lower than 550° C., thereby forming a film of silicon nitride having a film thickness smaller than 1.5 nm; and depositing a film of amorphous tantalum pentoxide and then crystallizing said amorphous tantalum pentoxide. The silicon nitride film has improved resistance to oxidation and also has a reduced leakage current. As a result, the polysilicon bottom electrode becomes resistant to oxidation and the storage capacitor increases in capacitance and decreases in leakage current.",
  "claims": [
    "1. A semiconductor integrated circuit including a plurality of capacitive elements, each element comprised of: a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; and a dielectric film of laminate structure comprised of a first dielectric whose principal component is silicon nitride and a second dielectric whose principal component is tantalum pentoxide, wherein said first dielectric is a silicon nitride film which is formed by direct nitriding of a surface of said semispherical silicon crystals and said tantalum pentoxide is a hexagonal δ-phase crystalline.",
    "2. The semiconductor integrated circuit as defined in claim 1, wherein the first dielectric has a film thickness larger than 1 nm.",
    "3. The semiconductor integrated circuit as defined in claim 1, wherein the second dielectric is crystallized and the crystal has a dielectric constant higher than 50.",
    "4. The semiconductor integrated circuit as defined in claim 1, wherein each capacitive element is further comprised of: an upper electrode, wherein said upper electrode faces the bottom electrode with the dielectric film interposed between the upper and bottom electrode formed from titanium nitride.",
    "5. A semiconductor integrated circuit including a plurality of capacitive elements, each element comprising: a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; and a dielectric film of laminate structure comprised of a first dielectric whose principal component is silicon nitride and a second dielectric whose principal component is tantalum pentoxide, wherein each capacitive element has a capacitance larger than 25 fF/μm 2 and said silicon nitride is formed by direct nitriding of a surface of said semispherical silicon crystals and said tantalum pentoxide is a hexagonal δ-phase crystalline.",
    "6. The semiconductor integrated circuit as defined in claim 5, wherein the first dielectric has a film thickness larger than 1 nm.",
    "7. The semiconductor integrated circuit as defined in claim 5, wherein the second dielectric is crystallized and the crystal has a dielectric constant higher than 50.",
    "8. The semiconductor integrated circuit as defined in claim 5, wherein each capacitive element is further comprised of: an upper electrode, wherein said upper electrode faces the bottom electrode with the dielectric film interposed between the upper and bottom electrode formed from titanium nitride.",
    "9. A semiconductor integrated circuit including a plurality of capacitive elements, each element comprised of: a bottom electrode of phosphorus-doped polysilicon; and a dielectric film of laminate structure comprised of a first dielectric whose principal component is silicon nitride and a second dielectric whose principal component is tantalum pentoxide, wherein said silicon nitride film is formed by direct nitriding of a surface of said phosphorus-doped polysilicon and said tantalum pentoxide is a hexagonal δ-phase crystalline.",
    "10. A semiconductor integrated circuit including a plurality of each element comprised of: a bottom electrode of phosphorus-doped polysilicon; and a dielectric film of laminate structure consisting of a first dielectric whose principal component is silicon nitride and a second dielectric whose principal component is tantalum pentoxide, wherein each of said capacitive elements has a capacitance larger than 12 fF/μm 2 and said silicon nitride is formed by direct nitriding of said phosphorus-doped polysilicon and said tantalum pentoxide is a hexagonal δ-phase crystalline."
  ],
  "cpc": [
    "H10D 1/712",
    "H10B 12/00",
    "H10B 12/315",
    "H10D 1/042",
    "H10D 1/716"
  ],
  "assignees": [
    "RENESAS TECH CORP"
  ],
  "filing_date": "2002-12-02",
  "publication_date": "2004-05-25",
  "grant_date": "2004-05-25",
  "priority_date": "2000-10-17",
  "application_number": "US-30735402-A",
  "family_id": "18799889",
  "citations": [
    "JPH04223366A",
    "JPH06244364A",
    "JPH11191612A",
    "JPH1126712A",
    "US5352623A",
    "US6057189A",
    "US6103567A",
    "US6218260B1",
    "US6387761B1",
    "US6403444B2",
    "US6448146B1",
    "US6583441B2"
  ]
}