Doping processes in metal interconnect structures
AssigneeLam Research Corporation
InventorsAniruddha Joi, Dries Dictus, Yezdi Dordi
Life of this patent
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Abstract
A metal interconnect structure is doped with zinc, indium, or gallium using top-down doping processes to improve diffusion barrier properties with minimal impact on line resistance. Dopant is introduced prior to metallization or after metallization. Dopant may be introduced by chemical vapor deposition on a liner layer at an elevated temperature prior to metallization, by chemical vapor deposition on a metal feature at an elevated temperature after metallization, or by electroless deposition on a copper feature after metallization. Application of elevated temperatures causes the metal interconnect structure to be doped and form a self-formed barrier layer or strengthen an existing diffusion barrier layer.
Claims7
A method of forming a self-formed barrier layer, the method comprising:
- receiving a substrate having a recess in a dielectric layer and a liner layer formed along sidewalls and a bottom surface of the recess;
- depositing, by chemical vapor deposition (CVD), a precursor containing zinc, indium, or gallium on the liner layer at a temperature to break down the precursor and to dope the liner layer with a dopant of zinc, indium, or gallium;
- and
- forming, at an interface between the liner layer and the dielectric layer while the substrate is exposed to the temperature, a self-formed barrier layer comprising a reaction product between the dielectric layer and the dopant.
Dependencies are inferred from the claim text.