United States Patent [w]
Nishioka
[54] FERROELECTRIC THIN-FILM CAPACITOR
[75] Inventor: Yasushiro Nishioka, Tsukuba, Japan
[73] Assignee: Texas Instruments Incorporated,
Dallas, Tex.
[21] Appl. No.: 08/851,053 [22] Filed: May 5, 1997
Related U.S. Application Data
[63] Continuation of application No. 08/508,941, Jul. 28, 1995, abandoned.
[30] Foreign Application Priority Data
Jul. 29, 1994 [JP] Japan 6-178819
[51] Int. CI. H01G 4/06
[52] U.S. CI 361/313; 361/321.5; 257/295;
252/520
[58] Field of Search 361/303, 305,
361/306.3, 311, 313, 321.5; 257/295, 296; 438/239, 240, 244; 29/25.42; 252/520
[56] References Cited
U.S. PATENT DOCUMENTS
5,122,477 6/1992 Wolters et al 437/60
5,443,030 8/1995 Ishihara et al 117/8
5,512,538 4/1996 Den et al 505/126
5,548,475 8/1996 Ushikubo et al 361/321.4
Primary Examiner—Kristine Kincaid
Assistant Examiner—Anthony Dinkins
Attorney, Agent, or Firm—-William B. Kempler; Richard L.
Donaldson
[57] ABSTRACT
A method for making a ferroelectric thin film capacitor. A Ti adhesive layer is formed on a silicon substrate covered with a silicon oxide layer. On this, a Pt film is deposited as a lower capacitor electrode, over which a ferroelectric film of high permittivity, such a crystallized BST film, is deposited by sputtering. Then an upper Pt electrode is deposited over the BST film by sputtering to form a capacitor. Finally, the capacitor is heat-treated in an oxidizing atmosphere to eliminate any leakage holes, that cause leakage current, in the ferroelectric thin film caused by the sputtering.
5 Claims, 3 Drawing Sheets
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