Capacitor and method for fabricating the same

• US 6,788,521 B2
• Filed: 09/26/2002
• Issued: 09/07/2004
• Est. Priority Date: 09/28/2001
• Status: Expired due to Fees

• Current Assignee: Fujitsu Quantum Devices Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Quantum Devices Limited (Fujitsu Limited)
• Inventors: Nishi, Masahiro
• Primary Examiner(s): Reichard, Dean A.
• Assistant Examiner(s): THOMAS, ERIC W
• Application Number:
  US10/254,836
• Publication Number:
  US 20030063428A1
• Time in Patent Office: 712 Days
• Field of Search: 257/308-312, 257/301, 257/303, 257/306, 361/311-313, 361/320, 361/321.4, 361/322, 361/306.4
• US Class Current: 361/301.4
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material

Abstract

A capacitor which includes a lower electrode 12 formed on a substrate 10; an insulation film 16 having an opening 24 on the lower electrode 12; a capacitor dielectric film 30 formed on the lower electrode 12 in the opening 24 and having a larger thickness at a peripheral part of the opening 24 than at a central part of the opening; and an upper electrode 32 formed on the capacitor dielectric film 30. Thus, degradation of the breakdown voltage and stress resistance of the peripheral part of the opening 24, which is due to the coverage of the capacitor dielectric film, can be suppressed.

Claims

1. A capacitor comprising:

a lower electrode formed on a substrate;

a first insulation film formed on the substrate with the lower electrode formed on, and having a first opening on the lower electrode;

a second insulation film formed an the first insulation film, and having a second opening in a region where the first opening is formed, the second opening being larger than the first opening, and an upper surface of the first insulation film being exposed at the peripheral part of the second opening;

a capacitor dielectric film formed on the lower electrode in the opening, and extended over the second insulation film; and

an upper electrode formed on the capacitor dielectric film, and extended over the second insulation film.

2. A capacitor according to claim 1, wherein

a film thickness of the first insulation film in a region where the second opening is formed is thinner than that in a region below the second insulation film.

3. A capacitor according to claim 1, wherein

the first insulation film is a cover insulation film which covers an interconnection or an electrode formed on the substrate in a region different from a region where the lower electrode is formed.

4. A capacitor comprising:

a lower electrode formed on a substrate;

a first insulation film formed on the substrate with the lower electrode formed on, and having a first opening on the lower electrode;

a second insulation film formed on the first insulation film, and having a second opening in a region where the first opening is formed;

a capacitor dielectric film formed on the lower electrode in the first opening and extended over the second insulation film; and

an upper electrode formed on the capacitor dielectric film, and extended over the second insulation film,

the first opening and the second opening being formed in a region containing a region where the lower electrode is formed; and

which further comprises;

a sidewall insulation film formed on a side wall of the lower electrode, the sidewall insulation film being formed of the same insulation film as the, first insulation film and spaced from the first insulation film.

5. A capacitor according to claim 4, wherein

the first insulation film is a cover insulation film which covers an interconnection or an electrode formed on the substrate in a region different from a region where the lower electrode is formed.