Method for production of semiconductor device

• US 6,306,756 B1
• Filed: 05/26/2000
• Issued: 10/23/2001
• Est. Priority Date: 06/21/1994
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tsutsumi, Junsei, Shimamura, Keizo, Okano, Haruo, Ito, Sachiyo, Wada, Junichi, Hasunuma, Masahiko, Hayasaka, Nobuo, Kajita, Akihiro, Kaneko, Hisashi
• Primary Examiner(s): QUACH, TUAN N
• Application Number:
  US09/580,922
• Time in Patent Office: 515 Days
• Field of Search: 438/632, 438/633, 438/646, 438/650, 438/687
• US Class Current: 438/632
• CPC Class Codes: H01L 21/76882 Reflowing or applying of pressure to better fill the contact hole

Abstract

A method for the production of a semiconductor device having an electrode line formed in a semiconducting substrate is disclosed which comprises preparing a semiconducting substrate having trenches and/or contact holes formed preparatorily in a region destined to form the electrode line, forming a conductive film formed mainly of at least one member selected from among Cu, Ag, and Au on the surface of the semiconducting substrate, heat-treating the superposed Cu film while supplying at least an oxidizing gas thereto thereby flowing the Cu film and causing never melting to fill the trenches and/or contact holes, and removing by polishing the part of the conductive film which falls outside the region of the electrode line and completing the electrode lines consequently. During the heat treatment, a reducing gas is supplied in addition to the oxidizing gas to induce a local oxidation-reduction reaction and fluidify and/or flow the conductive film and consequently accomplish the embodiment of the conductive film in the trenches. The formation of the interconnection is also accomplished by forming a conductive film on the surface of a semiconducting substrate having trenches formed therein, exerting thereon uniaxial stress from above the semiconducting substrate, heat treating the formed conductive film thereby flowing the conductive film, to fill the trenches, and polishing the surface of the semiconducting substrate.

Claims

1. A method for manufacturing a semiconductor device having an electrode line formed on a semiconducting substrate, comprising:

forming at least either of a trench and a contact hole in a region destined to form said electrode line on said semiconducting substrate,

heating said semiconducting substrate having at least either of said trench and said contact hole formed thereon and supplying at least an oxidizing gas and, at the same time, depositing a conductive film selected from the group consisting of Cu, Ag, and Au, causing at least one member selected from the group consisting of Cu, Ag, and Au to flow into said trench and/or said contact hole thereby forming said conductive film comprising at least one member selected from the group consisting of Cu, Ag, and Au, and

removing by polishing the part of said conductive film falling outside the region destined to form said electrode line thereby completing said electrode line.

2. The method according to claim 1, wherein supplying at least an oxidizing gas further includes supplying a reducing gas.

3. The method according to claim 2, wherein the amounts of said reducing gas and said oxidizing gas to be supplied are so controlled that the partial pressure of said oxidizing gas is greater than the equilibrium between the partial pressure of said oxidizing gas and the partial pressure of said reducing gas on the surface of said semiconducting substrate in the former of the step of film formation and the partial pressure of said reducing gas is greater than the equilibrium between the partial pressure of said oxidizing gas and the partial pressure of said reducing gas on the surface of said semiconducting substrate in the latter of said step of film formation.

4. The method according to claim 1, wherein the partial pressure of the oxidizing gas is smaller than the equilibrium partial pressure for oxidation of the conductive film in the process of the heating.

5. The method according to claim 4, wherein the partial pressure of the oxidizing gas is in the range of from 1×

10<sup>−

7</sup> to 5×

10<sup>−

5</sup> Torr.

6. The method according to claim 1, wherein the step of forming the conductive film comprising at least one member selected from the group consisting of Cu, Ag and Au on the semiconducting substrate comprises a step of forming a first conductive film of a substance whose oxide manifests electrical conductivity on the semiconducting substrate as an undercoating layer.

7. The method according to claim 6, wherein said first conductive film is formed through the medium of a barrier layer and the substance forming said first conductive film is such that the amount of change in the Gibbs free energy in the oxidizing reaction thereof with said oxidizing gas has a negative magnitude and the absolute value thereof is greater than the absolute value of the amount of change in the Gibbs free energy in the oxidizing reaction of said barrier layer.

8. The method according to claim 7, wherein the substance forming said first conductive film is at least one member selected from the group consisting of La, Nd, and Sm.

9. The method according to claim 1, further comprising:

forming a primary film selected from the group consisting of a metal film containing oxygen and mainly containing at least one selected from the group consisting of Cu, Ag, and Au and a metal oxide film mainly containing at least one selected from the group consisting of Cu, Ag and Au on the surface of the semiconducting substrate having at least either of the trench and the contact hole formed thereon, after forming at least either of the trench and the contact hole.

10. The method according to claim 9, wherein supplying at least an oxidizing gas further includes supplying a reducing gas.