Integrated circuit capacitors having composite titanium oxide and tantalum pentoxide dielectric layers therein

• US 6,433,380 B2
• Filed: 07/11/2001
• Issued: 08/13/2002
• Est. Priority Date: 10/19/1998
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Shin, Dong-won
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): KESHAVAN, BELUR V
• Application Number:
  US09/903,153
• Publication Number:
  US 20010042878A1
• Time in Patent Office: 398 Days
• Field of Search: 257/310, 257/303, 257/296, 257/324, 257/325, 257/306, 438/396, 438/239, 438/240, 438/253, 438/399, 438/310, 361/313
• US Class Current: 257/310
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02326 into a nitride layer, e.g. changing SiN to SiON
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31691 with perovskite structure
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H10B 12/315 with the capacitor higher than a bit line

Abstract

Methods of forming integrated circuit capacitors (e.g., DRAM capacitors) include the steps of forming a first capacitor electrode (e.g., polysilicon electrode) on a substrate and then forming a titanium nitride layer on the first capacitor electrode. A tantalum pentoxide dielectric layer is then formed on an upper surface of the titanium nitride layer. A step is then performed to convert the underlying titanium nitride layer into a titanium oxide layer. A second capacitor electrode is then formed on the tantalum pentoxide layer. The step of converting the titanium nitride layer into a titanium oxide layer is preferably performed by annealing the tantalum pentoxide layer in an oxygen ambient in a range between about 700° C. and 900° C. This oxygen ambient provides free oxygen to fill vacancies within the tantalum oxide layer and also provides free oxygen which diffuses into the underlying titanium nitride layer.

Claims

1. An integrated circuit capacitor, comprising

a first capacitor electrode;

a silicon oxynitride layer on said first capacitor electrode;

a titanium oxide layer on said silicon oxynitride layer;

a tantalum pentoxide layer on said silicon oxynitride layer; and

a second capacitor electrode on said tantalum pentoxide.

2. The integrated circuit capacitor of claim 1, further comprising a titanium nitride layer extending between the first capacitor electrode and the silicon oxynitride layer.

3. An integrated circuit capacitor, comprising

a first capacitor electrode;

a silicon oxynitride layer on a first portion of said first capacitor electrode;

a titanium oxide layer on a second portion of said first capacitor electrode;

a tantalum pentoxide layer on said silicon oxynitride layer and said titanium oxide layer, opposite said first capacitor electrode; and

a second capacitor electrode on said tantalum pentoxide layer, opposite said silicon oxynitride layer and said titanium oxide layer.

4. The integrated circuit capacitor of claim 3, further comprising a titanium nitride layer extending between the second portion of the first capacitor electrode and the titanium oxide lay.