Method of magnetic tunneling junction pattern layout for magnetic random access memory

US7508700B2 · kind B2 · utility

Assignee

• MagIC Technologies, Inc. · US

Inventors

• Tom Zhong · Saratoga, US
• Terry Kin Ting Ko · South San Francisco, US
• Chyu-Jiuh Torng · Pleasanton, US
• Wai-Ming J. Kan · San Ramon, US
• Adam Zhong · Milpitas, US

Key dates

• Filing date: Mar 15, 2007
• Grant date: Mar 24, 2009
• Expiry date: Sep 28, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S977/935

Abstract

An MTJ pattern layout for a memory device is disclosed that includes two CMP assist features outside active MTJ device blocks. A first plurality of dummy MTJ devices is located in two dummy bands formed around an active MTJ device block. The inner dummy band is separated from the outer dummy band by the MTJ ILD layer and has a MTJ device density essentially the same as the MTJ device block. The outer dummy band has a MTJ device density at least 10% greater than the inner dummy band. The inner dummy band serves to minimize CMP edge effect in the MTJ device block while the outer dummy band improves planarization. A second plurality of dummy MTJ devices is employed in contact pads outside the outer dummy band and is formed between a WL ILD layer and a BIT ILD layer thereby minimizing delamination of the MTJ ILD layer.