Leakage reduction in DRAM MIM capacitors

US8574998B2 · kind B2 · utility

Assignees

• INTERMOLECULAR, INC. · US
• ELPIDA MEMORY, INC. · JP

Inventors

• Sandra G. Malhotra · San Jose, US
• Kenichi Koyanagi · Kure, JP
• Hiroyuki Ode · Kure, JP
• Xiangxin Rui · Campbell, US
• Takashi Arao · Tokushima, JP
• Naonori Fujiwara · Tokyo, JP

Key dates

• Filing date: Dec 5, 2011
• Grant date: Nov 5, 2013
• Expiry date: Mar 22, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01G4/33
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for reducing the leakage current in DRAM MIM capacitors comprises forming a multi-layer dielectric stack from an amorphous highly doped material, an amorphous high band gap material, and a lightly or non-doped material. The highly doped material will remain amorphous (<30% crystalline) after an anneal step. The high band gap material will remain amorphous (<30% crystalline) after an anneal step. The lightly or non-doped material will become crystalline (≧30% crystalline) after an anneal step. The high band gap material is formed between the amorphous highly doped material and the lightly or non-doped material and provides an intermediate barrier to conduction through the multi-layer dielectric stack.