US 9,318,346 B2 · CMP polishing liquid and polishing method

Abstract

The CMP polishing liquid containing a medium and silica particles as an abrasive grain dispersed into the medium. The silica particles have a silanol group density of 5.0/nm2 or less and the biaxial average primary particle diameter when arbitrary 20 silica particles are selected from an image obtained by scanning electron microscope observation is 25 to 55 nm. The association degree of the silica particles is 1.1 or more. The CMP polishing liquid has the high barrier film polishing speed, the favorable abrasive grain dispersion stability, and the high interlayer dielectric polishing speed. The CMP polishing liquid can provide a method of producing semiconductor substrates or the like, that have excellent microfabrication, thin film formation, dimension accuracy, electric property and high reliability with low cost.

Claims37

Dependent claims

A polishing method comprising:

a polishing step of removing at least a part of a barrier conductive film and a part of an interlayer dielectric by supplying a CMP polishing liquid, wherein the CMP polishing liquid comprises a medium and silica particles as an abrasive grain dispersed into the medium, wherein:
(A2) the silica particles have a silanol group density of less than 5.0/nm2 and are not subjected to any surface treatment;
(B2) a biaxial average primary particle diameter when arbitrary 20 silica particles are selected from an image obtained by scanning electron microscope observation is 60 nm or less;
and
(C2) an association degree of the silica particles is 1.20 or less or from 1.40 to 1.80.

2 more elements

A polishing method comprising:

a mixing step of mixing a CMP polishing liquid concentrate with a diluting liquid, an additive liquid, or both of the diluting liquid and the additive liquid to prepare a CMP polishing liquid at a 3-fold dilution or a higher;
and
a polishing step of removing at least a part of a barrier conductive film and a part of an interlayer dielectric by supplying the CMP polishing liquid, wherein the CMP polishing liquid comprises a medium and silica particles as an abrasive grain dispersed into the medium, wherein:
(A2) the silica particles have a silanol group density of less than 5.0/nm2 and are not subjected to any surface treatment;
(B2) a biaxial average primary particle diameter when arbitrary 20 silica particles are selected from an image obtained by scanning electron microscope observation is 60 nm or less;
and
(C2) an association degree of the silica particles is 1.20 or less or from 1.40 to 1.80.

4 more elements

Dependencies are inferred from the claim text.

CMP polishing liquid and polishing method

Life of this patent

CMP polishing liquid and polishing method

Life of this patent

Abstract

Claims37