Multiply spin-coated ultra-thick hybrid hard mask for sub 60nm MRAM devices
First Claim
1. A method for etching a magnetic tunneling junction (MTJ) structure, the method comprising:
- providing a MTJ stack on a substrate;
depositing a metal hard mask layer having a first thickness on the MTJ stack;
depositing a dielectric hard mask layer on the metal hard mask layer;
forming a hybrid hard mask on the dielectric hard mask layer wherein the hybrid hard mask comprises a plurality of spin-on carbon layers alternating with a plurality of spin-on silicon layers, wherein a topmost layer of the hybrid hard mask is a silicon layer;
forming a photo resist pattern on the hybrid hard mask;
first etching portions of the topmost silicon layer of the hybrid hard mask exposed by the photo resist pattern using a first etching chemistry;
thereafter second etching the plurality of spin-on carbon layers and the plurality of spin-on silicon layers of the hybrid hard mask exposed by the photo resist pattern using a second etching chemistry, wherein the second etching chemistry etches away the photo resist pattern; and
thereafter etching portions of each of the dielectric hard mask, the metal hard mask, and the MTJ stack exposed by the hybrid hard mask to form a MTJ device and overlying top electrode, wherein the metal hard mask layer remaining has a second thickness no less than 80% of the first thickness.
2 Assignments
0 Petitions
Accused Products
Abstract
A metal hard mask layer is deposited on a MTJ stack on a substrate. A hybrid hard mask is formed on the metal hard mask layer, comprising a plurality of spin-on carbon layers alternating with a plurality of spin-on silicon layers wherein a topmost layer of the hybrid hard mask is a silicon layer. A photo resist pattern is formed on the hybrid hard mask. First, the topmost silicon layer of the hybrid hard mask is etched where is it not covered by the photo resist pattern using a first etching chemistry. Second, the hybrid hard mask is etched where it is not covered by the photo resist pattern wherein the photoresist pattern is etched away using a second etch chemistry. Thereafter, the metal hard mask and MTJ stack are etched where they are not covered by the hybrid hard mask to form a MTJ device and overlying top electrode.
-
Citations
20 Claims
-
1. A method for etching a magnetic tunneling junction (MTJ) structure, the method comprising:
-
providing a MTJ stack on a substrate; depositing a metal hard mask layer having a first thickness on the MTJ stack; depositing a dielectric hard mask layer on the metal hard mask layer; forming a hybrid hard mask on the dielectric hard mask layer wherein the hybrid hard mask comprises a plurality of spin-on carbon layers alternating with a plurality of spin-on silicon layers, wherein a topmost layer of the hybrid hard mask is a silicon layer; forming a photo resist pattern on the hybrid hard mask; first etching portions of the topmost silicon layer of the hybrid hard mask exposed by the photo resist pattern using a first etching chemistry; thereafter second etching the plurality of spin-on carbon layers and the plurality of spin-on silicon layers of the hybrid hard mask exposed by the photo resist pattern using a second etching chemistry, wherein the second etching chemistry etches away the photo resist pattern; and thereafter etching portions of each of the dielectric hard mask, the metal hard mask, and the MTJ stack exposed by the hybrid hard mask to form a MTJ device and overlying top electrode, wherein the metal hard mask layer remaining has a second thickness no less than 80% of the first thickness. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A method for etching a magnetic tunneling junction (MTJ) structure, the method comprising:
-
providing a MTJ stack on a substrate; depositing a metal hard mask layer on the MTJ stack; forming a hybrid hard mask on the metal hard mask layer, wherein the hybrid hard mask includes a plurality of spin-on carbon layers alternating with a plurality of spin-on silicon layers, wherein a topmost layer of the hybrid hard mask is a silicon layer; forming a photo resist pattern on the hybrid hard mask, wherein the photo resist pattern has a first pattern size; first etching the topmost silicon layer of the hybrid hard mask at portions thereof that are exposed by the photo resist pattern, wherein after the first etching, the photo resist pattern has a second pattern size smaller than said first pattern size; thereafter second etching the hybrid hard mask at portions thereof that are exposed by the photo resist pattern, wherein the photoresist pattern is etched away, and wherein a remaining portion of the hybrid hard mask has a third pattern size smaller than the second pattern size; and thereafter etching the metal hard mask and the MTJ stack at portions thereof that are exposed by the hybrid hard mask to form a MTJ device and overlying top electrode having a MTJ pattern size smaller than the third pattern size. - View Dependent Claims (7, 8, 9, 10)
-
-
11. A method for etching a magnetic tunneling junction (MTJ) structure, the method comprising:
-
providing a MTJ stack on a substrate; depositing a metal hard mask layer on the MTJ stack; depositing a dielectric hard mask on the metal hard mask; forming a hybrid hard mask on the metal hard mask layer, the forming the hybrid hard mask including; spin-coating a first carbon layer; spin-coating a first silicon layer on said first carbon layer; spin-coating a second carbon layer on said first silicon layer; and spin-coating a topmost silicon layer on said second carbon layer; forming a photo resist pattern on the hybrid hard mask, wherein the photo resist pattern has a first pattern size; first etching the topmost silicon layer of the hybrid hard mask where it is not covered by the photo resist pattern, wherein after the etching, the photo resist pattern and the topmost silicon layer have a second pattern size smaller than said first pattern size; thereafter second etching remaining the hybrid hard mask, wherein after the second etching, the photo resist pattern has been removed and the hybrid hard mask has a third pattern size smaller than the second pattern size; and thereafter etching the dielectric hard mask, the metal hard mask, and the MTJ stack where it is not covered by the hybrid hard mask to form a MTJ device and overlying top electrode having a MTJ pattern size smaller than the third pattern size. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification