Semiconductor device including a coupled dielectric layer and metal layer, method of fabrication thereof, and material for coupling a dielectric layer and a metal layer in a semiconductor device
View Patent ↗A passivating coupling material for, on the one hand, passivating a dielectric layer in a semiconductor device, and on the other hand, for permitting or at least promoting liquid phase metal deposition thereon in a subsequent process step. In a particular example, the dielectric layer may be a porous material having a desirably decreased dielectric constant k, and the passivating coupling material provides steric shielding groups that substantially block the adsorption and uptake of ambient moisture into the porous dielectric layer. The passivating coupling materials also provides metal nucleation sides for promoting the deposition of a metal thereon in liquid phase, in comparison with metal deposition without the presence of the passivating coupling material. The use of a liquid phase metal deposition process facilitates the subsequent manufacture of the semiconductor device. In one example, the passivating coupling material has multiple Si atoms in its chemical composition, which desirably increases the thermal stability of the material.
1. A semiconductor device comprising:
a semiconductor substrate; and
a passivated dielectric layer formed on the semiconductor substrate;
wherein the dielectric layer is passivated with a passivating coupling material, the coupling material comprising an organosilane, according to the general formula:
in which:
n is an integer equal to or greater than 1,
each Si is a silicon atom;
X 1 is a functional group able to react with a surface hydroxyl site of the dielectric material,
Y 1 is either:
X 2 , which is a further functional group able to react with a surface hydroxyl site of the dielectric material,
H, which is a hydrogen atom, or
R 1 , which is an organic apolar group or branch;
Y 2 is either:
X 3 , which is a further functional group able to react with a surface hydroxyl site of the dielectric material,
H, which is a hydrogen atom, or
R 2 , which is an organic apolar group or branch,
B, the presence of which is optional, is a bridging group,
Z 1 is either:
R 3 , which is an organic apolar group or branch,
H, which is a hydrogen atom, or
L 1 , which is a ligand having an electron donor functionality and is able to act as a metal nucleation site,
Z 2 is either:
R 4 , which is an organic apolar group or branch,
H, which is a hydrogen atom, or
L 2 , which is a ligand haying an electron donor functionality and which is able to act as a metal nucleation site, and
L is a ligand able to act as a metal nucleation site.
2. A semiconductor device according to claim 1 , characterized in that the dielectric layer is porous.
3. A semiconductor device according to claim 2 , characterized in that the porous dielectric layer is made from any one of carbonated silicon dioxide (SiOC), tetraethylorthosilicate glass (TEOS), and fluorine-doped tetraethylorthosilicate glass (FTEOS).
4. A semiconductor device according to claim 1 , characterized in that it further comprises a metal layer formed on the passivated dielectric layer.
5. A semiconductor device according to claim 4 , characterized in that the passivating coupling material provides nucleation sites supporting the formation of the metal layer.
6. A method of manufacturing a semiconductor device comprising:
forming a dielectric layer on a semiconductor substrate; and
passivating the dielectric layer,
wherein passivating the dielectric layer comprises applying a passivating coupling material on a surface of the dielectric layer
wherein the coupling material comprises an organosilane, according to the general formula:
in which:
n is an integer equal to or greater than 1,
each Si is a silicon atom;
X 1 is a functional group able to react with a surface hydroxyl site of the dielectric material,
Y 1 is either:
X 2 , which is a further functional group able to react with a surface hydroxyl site of the dielectric material,
H, which is a hydrogen atom, or
R 1 , which is an organic apolar group or branch;
Y 2 is either:
X 3 , which is a further functional group able to react with a surface hydroxyl site of the dielectric material,
H, which is a hydrogen atom, or
R 2 , which is an organic apolar group or branch,
B, the presence of which is optional, is a bridging group,
Z 1 is either:
R 3 , which is an organic apolar group or branch,
H, which is a hydrogen atom, or
L 1 , which is a ligand having an electron donor functionality and is able to act as a metal nucleation site,
Z 2 is either:
R 4 , which is an organic apolar group or branch,
H, which is a hydrogen atom, or
L 2 , which is a ligand having an electron donor functionality and which is able to act as a metal nucleation site, and
L is a ligand able to act as a metal nucleation site.
7. A method of claim 6 , wherein the dielectric layer is made from a porous material, characterized in that the passivating coupling material functions to seal a porosity of the porous dielectric layer so as to retard the uptake of moisture into the porous dielectric layer.
8. A method according to claim 7 , wherein the dielectric layer is made from any one of carbonated silicon dioxide (SiOC), tetraethylorthosilicate glass (TEOS), and fluorine-doped tetraethylorthosilicate glass (FTEOS).
9. A method according to claim 6 , characterized in that it further comprises forming a metal layer on the passivated dielectric layer using a liquid-phase metal deposition process.
10. A method according to claim 9 , characterized in that forming a metal layer on the passivated dielectric layer comprises a liquid-phase metal deposition process performed at a temperature of less than about 80° C.
11. A method according to claim 6 , characterized in that passivating the dielectric layer comprises applying an aqueous solution containing the passivating coupling material on the surface of the dielectric layer.
12. A method according to claim 11 , wherein passivating the dielectric layer comprises reacting the passivating coupling material contained in the aqueous solution faster than the dielectric material can adsorb water.
13. A method according to claim 11 , characterized in that it further comprises removing one or both of polymeric residues and metallic residues before applying the passivating coupling material.
14. A method according to claim 13 , characterized in that the aqueous solution containing the passivating coupling material additionally contains at least one cleaning composition for removing one or both of polymeric residues and metallic residues.
15. A method according to claim 6 , characterized in that the passivating coupling material is applied in a gas phase.
16. A method according to claim 15 , wherein the passivating coupling material is combined with a carrier gas.
17. A method according to claim 6 , characterized in that the passivating coupling material is applied as a spray in a predetermined atmosphere.
18. A method according to claim 17 , wherein the predetermined atmosphere is an inert atmosphere.
19. A semiconductor device manufactured according to the method of claim 6 .