US Patent Application 18232027. SELF-ALIGNED ENCAPSULATION HARD MASK TO SEPARATE PHYSICALLY UNDER-ETCHED MTJ CELLS TO REDUCE CONDUCTIVE RE-DEPOSITION simplified abstract

SELF-ALIGNED ENCAPSULATION HARD MASK TO SEPARATE PHYSICALLY UNDER-ETCHED MTJ CELLS TO REDUCE CONDUCTIVE RE-DEPOSITION

Organization Name

Taiwan Semiconductor Manufacturing Company, Ltd.==Inventor(s)==

[[Category:Yi Yang of Fremont CA (US)]]

[[Category:Dongna Shen of San Jose CA (US)]]

[[Category:Vignesh Sundar of Fremont CA (US)]]

[[Category:Yu-Jen Wang of San Jose CA (US)]]

SELF-ALIGNED ENCAPSULATION HARD MASK TO SEPARATE PHYSICALLY UNDER-ETCHED MTJ CELLS TO REDUCE CONDUCTIVE RE-DEPOSITION - A simplified explanation of the abstract

This abstract first appeared for US patent application 18232027 titled 'SELF-ALIGNED ENCAPSULATION HARD MASK TO SEPARATE PHYSICALLY UNDER-ETCHED MTJ CELLS TO REDUCE CONDUCTIVE RE-DEPOSITION

Simplified Explanation

The patent application describes a method for etching a magnetic tunneling junction (MTJ) structure. Here are the key points:

• The MTJ structure consists of a stack of layers, including a pinned layer, a barrier layer, and a free layer.
• A bottom electrode is deposited, followed by the MTJ stack and a top electrode layer.
• A hard mask is then deposited on top of the electrode layer.
• The electrode layer and hard mask are etched to create a pattern.
• The MTJ stack is then etched, stopping at or within the pinned layer.
• An encapsulation layer is deposited and etched, leaving a self-aligned hard mask on the sidewalls of the partially etched MTJ stack.
• Finally, the remaining MTJ stack not covered by the hard mask and self-aligned hard mask is etched to complete the MTJ structure.

Original Abstract Submitted

A method for etching a magnetic tunneling junction (MTJ) structure is described. A MTJ stack is deposited on a bottom electrode wherein the MTJ stack comprises at least a pinned layer, a barrier layer on the pinned layer, and a free layer on the barrier layer, A top electrode layer is deposited on the MTJ stack. A hard mask is deposited on the top electrode layer. The top electrode layer and hard mask are etched. Thereafter, the MTJ stack not covered by the hard mask is etched, stopping at or within the pinned layer. Thereafter, an encapsulation layer is deposited over the partially etched MTJ stack and etched away on horizontal surfaces leaving a self-aligned hard mask on sidewalls of the partially etched MTJ stack. Finally, the remaining MTJ stack not covered by hard mask and self-aligned hard mask is etched to complete the MTJ structure.