Polishing composition for semiconductor processing and method of polishing a substrate

1 . A composition for semiconductor processing, the composition comprising:

polishing particles, water, and a biocide,

wherein the polishing particles comprise colloidal silica particles having a surface modified with an epoxy silane and an amino silane,

wherein the biocide comprises a first biocide and a second biocide,

wherein the first biocide comprises benzisothiazolinone (BIT), and

wherein the second biocide comprises sodium hypochlorite.

2 . The composition of claim 1 , wherein the biocide comprises less than 0.16 parts by weight based on 100 parts by weight of the polishing particles.

3 . The composition of claim 1 , wherein the first biocide and the second biocide comprise a weight ratio of 1:0.1 to 1.0.

4 . The composition of claim 1 , wherein the first biocide comprises 0.01 to 0.15 parts by weight, based on 100 parts by weight of the polishing particles.

5 . The composition of claim 1 , wherein the second biocide comprises 0.005 to 0.1 parts by weight, based on 100 parts by weight of the polishing particles.

6 . The composition of claim 1 ,

wherein the colloidal silica has a diameter (D 50 ) of 20 nm to 60 nm, and

wherein the colloidal silica comprises at least 2 wt % based on a total composition for semiconductor processing.

7 . The composition of claim 6 , wherein the composition for semiconductor processing has a pH of at least 2 and less than 4.5.

8 . The composition of claim 7 , wherein when the composition for semiconductor processing is left in an atmosphere of 60° C. for 12 hours, there are no more than 15 particles having a diameter of 5 μm or more per liter of the composition for semiconductor processing.

9 . The composition of claim 7 , wherein when the composition for semiconductor processing is left in an atmosphere of 60° C. for 12 hours, there are no more than 150 particles having a diameter of 1 μm per liter of the composition for semiconductor processing.

10 . The composition of claim 1 , wherein the composition for semiconductor processing further comprises a pad protector, and

wherein the pad protector comprises a sugar alcohol compound or a disaccharide compound.

11 . The composition of claim 1 , wherein the first biocide comprises 0.01 to 0.15 parts by weight, and the second biocide comprises 0.005 to 0.1 parts by weight, based on 100 parts by weight of the polishing particles, and

wherein the first biocide and the second biocide comprise a weight ratio of 1:0.1 to 1.0.

12 . The composition of claim 1 , wherein the first biocide comprises 0.01 to 0.15 parts by weight, and the second biocide comprises 0.005 to 0.1 parts by weight, based on 100 parts by weight of the polishing particles,

wherein the first biocide and the second biocide comprise a weight ratio of 1:0.1 to 1.0,

wherein the composition further comprises a pad protector which comprises a sugar alcohol compound or a disaccharide compound, and the composition for a semiconductor process comprises the pad protector in a range of 10 parts by weight to 200 parts by weight based on 100 parts by weight of the polishing particles.

13 . A method of polishing a substrate, the method comprising:

providing a polishing pad-mounted plate and a carrier receiving the substrate; and

producing a polished substrate by planarizing a surface of the substrate by a polishing surface of the polishing pad while rotating at least one of the plate and the carrier,

wherein the producing of the polished substrate is performed in the presence of a composition for semiconductor processing, and

wherein the composition for semiconductor processing is the composition of claim 1 .

14 . The method of claim 13 , wherein the surface of the substrate to be polished comprises an insulating film and a tungsten film,

wherein the polished substrate is a circular wafer having a diameter of 300 mm, and

wherein the polished substrate has no more than 70 tungsten defects on a surface of the polished substrate.

15 . The method of claim 13 , wherein the surface of the substrate to be polished comprises an insulating film and a tungsten film, and

wherein a ratio of a polishing rate of the tungsten film to a polishing rate of the insulating film is 1:11 to 15.