US2022013406A1PendingUtilityA1

Trapezoidal Interconnect at Tight BEOL Pitch

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Assignee: IBMPriority: Sep 17, 2019Filed: Sep 23, 2021Published: Jan 13, 2022
Est. expirySep 17, 2039(~13.1 yrs left)· nominal 20-yr term from priority
Inventors:Nicholas Anthony LanzilloHosadurga ShobhaHuai HuangJunli WangKoichi MotoyamaChristoher J. PennyLawrence A. Clevenger
H10W 20/4437H10P 50/667H10P 14/418H10W 20/425H10W 20/062H10W 20/435H10W 20/089H10W 20/033H10W 20/4403H10W 20/082H01L 21/32134H01L 21/76804H01L 21/76843H01L 23/5283H01L 21/76816
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Claims

Abstract

Techniques for forming trapezoidal-shaped interconnects are provided. In one aspect, a method for forming an interconnect structure includes: patterning a trench(es) in a dielectric having a V-shaped profile with a rounded bottom; depositing a liner into the trench(es) using PVD which opens-up the trench(es) creating a trapezoidal-shaped profile in the trench(es); removing the liner from the trench(es) selective to the dielectric whereby, following the removing, the trench(es) having the trapezoidal-shaped profile remains in the dielectric; depositing a conformal barrier layer into and lining the trench(es) having the trapezoidal-shaped profile; depositing a conductor into and filling the trench(es) having the trapezoidal-shaped profile over the conformal barrier layer; and polishing the conductor and the conformal barrier layer down to the dielectric. An interconnect structure is also provided.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
         1 . An interconnect structure, comprising:
 at least one trench patterned in a dielectric having a trapezoidal-shaped profile;   a conformal barrier layer lining the at least one trench having the trapezoidal-shaped profile; and   a conductor disposed over the conformal barrier layer in the at least one trench having the trapezoidal-shaped profile, wherein the conductor is selected from the group consisting of: cobalt (Co), ruthenium (Ru), and combinations thereof.   
     
     
         2 . The interconnect structure of  claim 1 , wherein the dielectric is selected from the group consisting of: silicon oxide (SiOx), organosilicate glass (SiCOH), porous organosilicate glass (pSiCOH) and combinations thereof. 
     
     
         3 . The interconnect structure of  claim 1 , wherein the conformal barrier layer comprises a material selected from the group consisting of: tantalum (Ta), tantalum nitride (TaN), titanium nitride (TiN). 
     
     
         4 . The interconnect structure of  claim 1 , wherein the conformal barrier layer has a thickness of less than about 20 Å. 
     
     
         5 . The interconnect structure of  claim 1 , wherein the conformal barrier layer has a thickness of from about 10 Å to about 15 Å, and ranges therebetween. 
     
     
         6 . The interconnect structure of  claim 1 , wherein a top surface of the conductor is coplanar with a top surface of the dielectric. 
     
     
         7 . The interconnect structure of  claim 1 , wherein a top of the conductor is wider than a bottom of the conductor. 
     
     
         8 . The interconnect structure of  claim 1 , wherein the conformal barrier layer fully separates the conductor from the dielectric. 
     
     
         9 . The interconnect structure of  claim 1 , wherein the conductor is in direct contact with the conformal barrier layer. 
     
     
         10 . An interconnect structure, comprising:
 at least one trench patterned in a dielectric having a trapezoidal-shaped profile;   a conformal barrier layer lining the at least one trench having the trapezoidal-shaped profile; and   a conductor disposed over the conformal barrier layer in the at least one trench having the trapezoidal-shaped profile, wherein the conductor comprises copper (Cu).   
     
     
         11 . The interconnect structure of  claim 10 , wherein the dielectric is selected from the group consisting of: silicon oxide (SiOx), organosilicate glass (SiCOH), porous organosilicate glass (pSiCOH) and combinations thereof. 
     
     
         12 . The interconnect structure of  claim 10 , wherein the conformal barrier layer comprises a material selected from the group consisting of: tantalum (Ta), tantalum nitride (TaN), titanium nitride (TiN). 
     
     
         13 . The interconnect structure of  claim 10 , wherein the conformal barrier layer has a thickness of less than about 20 Å. 
     
     
         14 . The interconnect structure of  claim 10 , wherein the conformal barrier layer has a thickness of from about 10 Å to about 15 Å, and ranges therebetween. 
     
     
         15 . The interconnect structure of  claim 10 , further comprising:
 a conformal wetting layer in the at least one trench having the trapezoidal-shaped profile over the barrier layer such that the conductor is disposed on the conformal wetting layer.   
     
     
         16 . The interconnect structure of  claim 15 , wherein the conformal wetting layer comprises a material selected from the group consisting of: cobalt (Co), ruthenium (Ru), and combinations thereof. 
     
     
         17 . The interconnect structure of  claim 15 , wherein the conformal wetting layer has a thickness of less than about 30 Å. 
     
     
         18 . The interconnect structure of  claim 15 , wherein the conformal wetting layer has a thickness of from about 15 Å to about 20 Å, and ranges therebetween. 
     
     
         19 . The interconnect structure of  claim 15 , wherein the conformal barrier layer and the conformal wetting layer fully separate the conductor from the dielectric. 
     
     
         20 . The interconnect structure of  claim 10 , wherein a top surface of the conductor is coplanar with a top surface of the dielectric.

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