Process for producing a strontium ruthenium oxide protective layer on a top electrode

US6674633B2 · kind B2 · utility

Assignee

• FUJITSU LIMITED · JP

Inventors

• Shan Sun · Wingdale, US
• George Hickert · Colorado Springs, US
• Katsuyoshi Matsuura · Tokyo, JP
• Takeyasu Saito · Kawasaki, JP
• Soichiro Ozawa · Yokohama, JP
• Naoyuki Satoh · Yokohama, JP
• Mitsushi Fujiki · Kawasaki, JP
• Satoru Mihara · Tokyo, JP
• Jeffrey Scott Cross · Yokohama, JP
• Yoshimasa Horii · Kawasaki, JP

Key dates

• Filing date: Feb 28, 2001
• Grant date: Jan 6, 2004
• Expiry date: Feb 28, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/682

Abstract

A method for the fabrication of a cap layer on a top electrode layer of a ferroelectric capacitor includes the steps of depositing an amorphous layer, usually made of Sr(x)Ru(y)O3, on the top electrode and then annealing the amorphous layer in two stages in order convert the amorphous layer into the cap layer. The first anneal is performed at 500° C. to 700° C. in a non-oxidizing atmosphere, such as nitrogen, and converts the amorphous layer into a crystallized layer of Sr(x)Ru(y)O3. The second anneal is performed at 300° C. to 500° C. in an oxidizing atmosphere, such as oxygen, and converts the crystallized layer into the cap layer. The method is applied to the formation of a ferroelectric capacitor element of an integrated semiconductor device.