Copper metallization of USLI by electroless process

Claim 1

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co, and alloys of Ni, Pd, Co; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu.

Claim 2

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co, and alloys of Ni, Pd, Co; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu.

Claim 7

A method of fabrication of a contact to a silicon substrate using electroless deposition comprising the steps of: a) forming an insulating layer over a substrate; b) forming a first photoresist layer having first openings over said insulating layer; c) forming a contact hole in said insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; d) forming a first activation layer on said exposed substrate in said contact hole; said first activation layer formed using a Pd containing solution; e) forming a Palladium (Pd) layer on said first activation layer; said Palladium (Pd) layer formed by plating or sputtering processes; f) removing said first photoresist layer; g) annealing said Palladium (Pd) layer and said first activation layer forming a Pd silicide layer in said contact hole on said substrate; h) forming a barrier layer over said Palladium (Pd) silicide layer; said barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co and alloys of Ni, Pd, Co; i) electrolessly depositing a first metal layer filling said contact hole; said first metal layer composed of Cu or Au on said barrier layer; j) forming a polysilicon layer over said first metal layer; k) depositing a Palladium (Pd) layer over said Polysilicon layer using a electroless or sputtering process; l) annealing said Palladium (Pd) layer and said polysilicon layer to form a Palladium silicide layer on said first metal layer; m) forming a second insulating layer over said first insulating layer; said second insulating layer having a second contact hole aligned with said first contact hole and exposing said Palladium silicide (PdSi x ) layer; n) selectively electroless plating a second metal layer over said first metal layer filling said second contact hole; said second metal comprising Cu or Au.

Claim 8

A method of fabrication of a contact to a silicon substrate using electroless deposition comprising the steps of: a) forming an insulating layer over a substrate; b) forming a first photoresist layer having first openings over said insulating layer; c) forming a contact hole in said insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; d) forming a first activation layer on said exposed substrate in said contact hole; said first activation layer formed using a Pd containing solution; e) forming a Palladium (Pd) layer on said first activation layer; said Palladium (Pd) layer formed by plating or sputtering processes; f) removing said first photoresist layer; g) annealing said Palladium (Pd) layer and said first activation layer forming a Pd silicide layer in said contact hole on said substrate; h) forming a barrier layer over said Palladium (Pd) silicide layer; said barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co and alloys of Ni, Pd, Co; i) electrolessly depositing a first metal layer filling said contact hole; said first metal layer composed of Cu or Au on said barrier layer; j) forming a polysilicon layer over said first metal layer; k) depositing a Palladium (Pd) layer over said Polysilicon layer using a electroless or sputtering process; l) annealing said Palladium (Pd) layer and said polysilicon layer to form a Palladium silicide layer on said first metal layer; m) forming a second insulating layer over said first insulating layer; said second insulating layer having a second contact hole aligned with said first contact hole and exposing said Palladium silicide (PdSi x ) layer; n) selectively electroless plating a second metal layer over said first metal layer filling said second contact hole; said second metal comprising Cu or Au.

Claim 11

A method of fabrication of a contact to a silicon substrate using electroless deposition comprising the steps of: a) forming an insulating layer over a substrate; b) forming a first photoresist layer having first openings over said insulating layer; c) forming a contact hole in said insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; d) forming a first activation layer on said exposed substrate in said contact hole; said first activation layer formed using a Pd containing solution; e) electrolessly plating a Pd layer on said first activation layer; said Palladium layer formed by platting or sputtering processes; f) removing said first photoresist layer; g) annealing said Palladium (Pd) layer and said first activation layer forming a Pd silicide layer in said contact hole on said substrate; h) forming a barrier layer over said Pd silicide layer; said barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co and alloys of Ni, Pd, Co; i) electrolessly depositing a first metal layer composed of Cu or Au on said barrier layer; j) forming an adhesion layer over said first metal layer; said adhesion layer composed of a material selected from the group consisting of Al or Ti; k) depositing an second activation layer over said adhesion layer using said activation layer formed using a PdCl 2 containing or zincate containing solution; l) forming a second insulating layer over said first insulating layer; said second insulating layer having a second contact hole aligned with said first contact hole and exposing said second activation layer; m) electroless plating a second metal layer over said first metal layer filling said second contact hole; said second metal comprised of Cu or Au.

Claim 12

A method of fabrication of a contact to a silicon substrate using electroless deposition comprising the steps of: a) forming an insulating layer over a substrate; b) forming a first photoresist layer having first openings over said insulating layer; c) forming a contact hole in said insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; d) forming a first activation layer on said exposed substrate in said contact hole; said first activation layer formed using a Pd containing solution; e) electrolessly plating a Pd layer on said first activation layer; said Palladium layer formed by platting or sputtering processes; f) removing said first photoresist layer; g) annealing said Palladium (Pd) layer and said first activation layer forming a Pd silicide layer in said contact hole on said substrate; h) forming a barrier layer over said Pd silicide layer; said barrier layer is composed of a material selected from the group consisting of Ni, Pd, Co and alloys of Ni, Pd, Co; i) electrolessly depositing a first metal layer composed of Cu or Au on said barrier layer; j) forming an adhesion layer over said first metal layer; said adhesion layer composed of a material selected from the group consisting of Al or Ti; k) depositing an second activation layer over said adhesion layer using said activation layer formed using a PdCl 2 containing or zincate containing solution; l) forming a second insulating layer over said first insulating layer; said second insulating layer having a second contact hole aligned with said first contact hole and exposing said second activation layer; m) electroless plating a second metal layer over said first metal layer filling said second contact hole; said second metal comprised of Cu or Au.

Claim 15

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of electroless Nickel and having a thickness in a range of between about 1800 and 2200 Å and is formed using a electroless solution comprising: Nickel sulfate at a concentration between 28 and 32 g/l, a Dimethlylamine Borane (DMAB) at a concentration between 2.8 and 32 g/l; Sodium citrate at a concentration between about 25-35 g/l, and Ammonium Chloride at a concentration between about 28-32 g/l, at a Temperature between 58 and 62° C., and at a pH Value between 5.9 and 6.1; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu.

Claim 16

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of electroless Nickel and having a thickness in a range of between about 1800 and 2200 Å and is formed using a electroless solution comprising: Nickel sulfate at a concentration between 28 and 32 g/l, a Dimethlylamine Borane (DMAB) at a concentration between 2.8 and 32 g/l; Sodium citrate at a concentration between about 25-35 g/l, and Ammonium Chloride at a concentration between about 28-32 g/l, at a Temperature between 58 and 62° C., and at a pH Value between 5.9 and 6.1; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu.

Claim 20

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; (2) said adhesion layer has a thickness in a range of between about 400 and 600 Å; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of electroless Nickel and having a thickness in a range of between about 1800 and 2200 Å and is formed using a electroless solution comprising: Nickel sulfate at a concentration between 28 and 32 g/l, a Dimethlylamine Borane (DMAB) at a concentration between 2.8 and 32 g/l; Sodium citrate at a concentration between about 25-35 g/l, and Ammonium Chloride at a concentration between about 28-32 g/l, at a Temperature between 58 and 62° C., and at a pH Value between 5.9 and 6.1; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; (1) said first metal is comprised of Cu and is formed using an electrolessly plating solution comprising: Copper Sulphate at a concentration in a range between about 6 and 7 g/L; Sodium citrate at a concentration between 15 and 15.8 g/l and Nickel Sulphate at a concentration between about 0.4 and 6.0 g/l and Sodium Hypophosphite at a concentration at a range between 10 and 11 g/L, and Boric acid with a concentration between 4.5 and 5.5 g/L; at a temp 62 and 68° C., and at a pH value between about 9.0 and 9.3; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu; (1) said first metal is comprised of Cu and is formed using an electrolessly plating solution comprising: Copper Sulphate at a concentration in a range between about 6 and 7 g/L; Sodium citrate at a concentration between 15 and 15.8 g/l and Nickel Sulphate at a concentration between about 0.4 and 6.0 g/l and Sodium Hypophosphite at a concentration at a range between 10 and 11 g/L, and Boric acid with a concentration between 4.5 and 5.5 g/L; at a temp 62 and 68° C., and at a pH value between about 9.0 and 9.3.

Claim 21

A method of fabrication of a contact to a silicon substrate ( 10 ) using electroless deposition comprising the steps of: a) forming a contact hole in an insulating layer exposing a substrate; said contact hole defined by sidewalls of said insulating layer; b) forming an adhesion layer on said sidewalls of said insulating layer and said exposed substrate; (1) said adhesion layer is composed of a material selected from the group consisting of Al, Al alloys, polysilicon, Ni, palladium silicide, and amorphous silicon; (2) said adhesion layer has a thickness in a range of between about 400 and 600 Å; c) electrolessly depositing a first barrier layer on said adhesion layer; (1) said first barrier layer is composed of electroless Nickel and having a thickness in a range of between about 1800 and 2200 Å and is formed using a electroless solution comprising: Nickel sulfate at a concentration between 28 and 32 g/l, a Dimethlylamine Borane (DMAB) at a concentration between 2.8 and 32 g/l; Sodium citrate at a concentration between about 25-35 g/l, and Ammonium Chloride at a concentration between about 28-32 g/l, at a Temperature between 58 and 62° C., and at a pH Value between 5.9 and 6.1; d) activating said first barrier layer using a PdCl 2 containing solution; e) selectively electrolessly plating a first metal over said first barrier layer filling said contact hole; said first metal deposited using an electroless plating process; said first metal layer is composed of a material selected from the group consisting Cu, Au and alloys of Cu or Au; (1) said first metal is comprised of Cu and is formed using an electrolessly plating solution comprising: Copper Sulphate at a concentration in a range between about 6 and 7 g/L; Sodium citrate at a concentration between 15 and 15.8 g/l and Nickel Sulphate at a concentration between about 0.4 and 6.0 g/l and Sodium Hypophosphite at a concentration at a range between 10 and 11 g/L, and Boric acid with a concentration between 4.5 and 5.5 g/L; at a temp 62 and 68° C., and at a pH value between about 9.0 and 9.3; f) forming a second insulating layer over said first insulating layer, said first metal, said first barrier layer and said adhesion layer; g) patterning said second insulating layer to form a via hole exposing said first metal; h) forming a second barrier layer over said first metal; said second barrier layer composed of a material selected from the group consisting of Ni, Pd or Co; i) activating said second barrier metal using a PdCl 2 containing solution; and j) selectively electroless plating a second metal over said first metal layer filling said via hole; said second metal comprised of Au or Cu; (1) said first metal is comprised of Cu and is formed using an electrolessly plating solution comprising: Copper Sulphate at a concentration in a range between about 6 and 7 g/L; Sodium citrate at a concentration between 15 and 15.8 g/l and Nickel Sulphate at a concentration between about 0.4 and 6.0 g/l and Sodium Hypophosphite at a concentration at a range between 10 and 11 g/L, and Boric acid with a concentration between 4.5 and 5.5 g/L; at a temp 62 and 68° C., and at a pH value between about 9.0 and 9.3.