Slurry for CMP, polishing method and method of manufacturing semiconductor device
Disclosed is a CMP slurry comprising a Cu oxidizing agent, a complexing agent for forming a Cu organic complex, a surfactant, an inorganic particle, and a resin particle containing polystyrene, having on the surface thereof a functional group of the same kind of polarity as that of the inorganic particle and having an average particle diameter of less than 100 nm, the resin particle being incorporated at a concentration of less than 1% by weight.
1. A polishing method comprising:
contacting a polishing surface of a semiconductor substrate with a polishing pad attached to a turntable; and
dropping a CMP slurry onto the polishing pad to polish the polishing surface, the CMP slurry comprising:
a Cu oxidizing agent;
a complexing agent forming a Cu organic complex;
a nonionic surfactant which is incorporated at a concentration of 0.1 wt % or less;
an inorganic particle; and
a resin particle which is incorporated at a concentration of less than 1 wt %, contains polystyrene, has on the surface thereof a functional group of the same kind of polarity as that of the inorganic particle and has an average particle diameter ranging from 20 to 50 nm,
wherein the complexing agent forms a hydrophobic protective film on the polishing surface, and the nonionic surfactant forms a hydrophilic protective film on the hydrophobic protective film.
2. The polishing method according to claim 1 , wherein the polishing surface contains Cu.
3. The polishing method according to claim 1 , wherein the resin particle in the CMP slurry is incorporated therein at a concentration ranging from 0.05 to 0.95 wt %.
4. The polishing method according to claim 1 , wherein the surface functional group of the resin particle in the CMP slurry includes at least one selected from the group consisting of a carboxylic group, a sulfonyl group and an amino group.
5. The polishing method according to claim 1 , wherein the nonionic surfactant in the CMP slurry has an HLB value of 10 to 18.
6. The polishing method according to claim 1 , wherein the nonionic surfactant in the CMP slurry has a weight average molecular weight of 10,000 or less.
7. A method of manufacturing a semiconductor device comprising:
forming an insulating film above a semiconductor substrate;
forming a recessed portion in the insulating film;
depositing a conductive material inside the recessed portion and above the insulating film to form a conductive layer; and
removing the conductive material which is deposited above the insulating film by CMP using a CMP slurry to selectively leave the conductive material in the recessed portion, the CMP slurry comprising:
a Cu oxidizing agent;
a complexing agent forming a Cu organic complex;
a nonionic surfactant which is incorporated at a concentration of 0.1 wt % or less;
an inorganic particle; and
a resin particle which is incorporated at a concentration of less than 1 wt %, contains polystyrene, has on the surface thereof a functional group of the same kind of polarity as that of the inorganic particle and has an average particle diameter ranging from 20 to 50 nm,
wherein the conductive material is Cu and the conductive layer is a Cu layer, the Cu oxidizing agent oxidizes a surface of the Cu layer to form an oxidized Cu, the complexing agent forms an organic complex with the oxidized Cu, the organic complex constituting a hydrophobic protective film, and the nonionic surfactant forms a hydrophilic protective film on the hydrophobic protective film.
8. The method according to claim 7 , wherein the conductive layer is a Cu film formed by plating.
9. The method according to claim 7 , wherein the recessed portion includes wiring trenches comprising a first wiring trench and a second wiring trench, the first wiring trench having a first line width and being densely formed in a first region, and the second wiring trench having a larger line width than that of the first wiring trench and being formed in a second region.
10. The method according to claim 9 , wherein the thickness of the conductive layer in the first region is larger than the thickness of the conductive layer in the second region.
11. The method according to claim 7 , wherein the nonionic surfactant in the CMP slurry has an HLB value of 10 to 18.
12. The method according to claim 7 , wherein the nonionic surfactant in the CMP slurry has a weight average molecular weight of 10,000 or less.