Gate-insulating film including oxide film

• US 6,445,033 B1
• Filed: 06/30/2000
• Issued: 09/03/2002
• Est. Priority Date: 06/30/1999
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Corporation
• Inventors: Hasegawa, Eiji
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): PHAM, HOAI V
• Application Number:
  US09/609,290
• Time in Patent Office: 795 Days
• Field of Search: 257/324, 257/327, 257/349, 257/368, 257/369, 257/405, 257/406, 257/410, 257/411, 438/216, 438/261, 438/287, 438/591
• US Class Current: 257/324
• CPC Class Codes: H01L 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence

Abstract

A gate-insulating film of the present invention is a gate-insulating film having a polycrystalline film made of a metal oxide, in which a grain boundary plane extending in parallel with the polycrystalline film is present at the position of a predetermined thickness of the polycrystalline film and grain boundaries extending in the film-thickness direction of polycrystals configuring the polycrystalline film are discontinuous at the grain boundary plane.

Claims

1. A gate-insulating film having a polycrystalline film made of a metal oxide, wherein a grain boundary plane extending in parallel with a plane of said polycrystalline film is present at a position of a predetermined thickness of said polycrystalline film and grain boundaries extending in film-thickness directions of polycrystals configuring said polycrystalline film are discontinuous on said grain boundary plane.

2. The gate-insulating film according to claim 1, wherein said oxide is a tantalum oxide.

3. A gate-insulating film including a silicon oxide film formed on a silicon substrate and a polycrystalline film made of an oxide formed on said silicon oxide film,

wherein said polycrystalline film has a laminate structure of polycrystalline layers polycrystallized after a plurality of amorphous layers made of said oxide are superposed and grain boundaries extending in said layer-thickness direction of said polycrystalline layers adjacent to each other in said layer-thickness direction are discontinuous with each other,

wherein said oxide is a tantalum oxide having a relative permittivity of 7.0 or more and said gate-insulating film has a thickness converted into silicon-oxide-film thickness of 5.0 nm or less.

4. A gate-insulating film including a polycrystalline film made of an oxide,

wherein said polycrystalline film has a laminate structure of polycrystalline layers polycrystallized after a plurality of amorphous layers made of said oxide are independently superposed and grain boundaries extending in said layer-thickness direction of said polycrystalline layers adjacent to each other in said layer-thickness direction are discontinuous with each other,

wherein said oxide is a tantalum oxide.

5. A gate-insulating film including a polycrystalline film made of an oxide,

wherein said polycrystalline film has a layer-thickness-directional grain size equal to an average grain size in a direction parallel with a layer and has a structure in which a plurality of polycrystalline layers whose thickness is equal to said layer-thickness-directional grain size, and grain boundaries extending in said layer-thickness direction of said polycrystalline layers adjacent to each other in said layer-thickness direction are discontinuous with each other,

wherein said oxide is a tantalum oxide.

6. A gate-insulating film including a silicon oxide film formed on a silicon substrate and a polycrystalline film made of an oxide formed on said silicon oxide film,

wherein said polycrystalline film has a laminate structure of polycrystalline layers polycrystallized after a plurality of amorphous layers made of said oxide are superposed and grain boundaries extending in said layer-thickness direction of said polycrystalline layers adjacent to each other in said layer-thickness direction are discontinuous with each other,

wherein said oxide is a tantalum oxide.