Capacitor comprising improved TaO.sub.x -based dielectric

• US 5,977,582 A
• Filed: 05/23/1997
• Issued: 11/02/1999
• Est. Priority Date: 05/23/1997
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: van Dover, Robert Bruce, Schneemeyer, Lynn Frances, Fleming, Robert McLemore
• Primary Examiner(s): Arroyo, Teresa M.
• Assistant Examiner(s): GUERRERO, MARIA F
• Application Number:
  US08/862,907
• Time in Patent Office: 893 Days
• Field of Search: 438/240, 257/532, 257/310, 257/296, 257/300, 257/309, 257/FOR 310, 257/FOR 532, 148/DIG. 14
• US Class Current: 257/310
• CPC Class Codes: H01G 4/08 Inorganic dielectrics
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

A dielectric layer consisting essentially of Ta, Al, oxygen and nitrogen can have advantageous properties that make such a layer useful for thin film capacitors, typically capacitors for Si integrated circuits. For instance, a significantly greater fraction of capacitors according to the invention than of prior art tantalum oxide capacitors can store a charge of 3 μcoulomb/cm². In a currently preferred embodiment, the dielectric layer has composition Ta_1-y Al_y O_x N_z, with y˜0.1, x˜2.4, and z˜0.02. The dielectric layer can be formed by sputter deposition or any other appropriate deposition technique, e.g., chemical vapor deposition.

Claims

1. Article comprising a capacitor comprising two electrically conductive members, and a first dielectric layer therebetween;

CHARACTERIZED IN THAT

the first dielectric layer consists essentially of tantalum (Ta), aluminum (Al), oxygen (O) and nitrogen (N).

2. Article according to claim 1, wherein the first dielectric layer has composition Ta_1-y Al_y O_x N_z, where 0.05≦

y≦

0.5, 2.0≦

x≦

2.5, and 0≦

z≦

0.1.

3. Article according to claim 2, wherein y is about 0.1, x is about 2.4 and z is about 0.02.

4. Article according to claim 1, wherein the article is a Si integrated circuit.

5. Article according to claim 1, wherein the capacitor is a member of a multi-capacitor sample, at least 75% of the members of the sample being capable of storing 3 μ

coulomb/cm² or more.

6. Article according to claim 1, wherein the capacitor further comprises at least one layer of a second dielectric material of composition different from the first dielectric layer.