US 8,075,372 B2Granted

Polishing pad with microporous regions

AssigneeCabot Microelectronics Corporation

InventorAbaneshwar Prasad

Life of this patent

Estimating the term…

Loading patent…

Abstract

The invention provides a polishing pad for chemical-mechanical polishing comprising a polymeric material comprising two or more adjacent regions, wherein the regions have the same polymer formulation and the transition between the regions does not include a structurally distinct boundary. In a first embodiment, a first region and a second adjacent region have a first and second non-zero void volume, respectively, wherein the first void volume is less than the second void volume. In a second embodiment, a first non-porous region is adjacent to a second adjacent porous region, wherein the second region has an average pore size of about 50 μm or less. In a third embodiment, at least two of an optically transmissive region, a first porous region, and an optional second porous region, are adjacent. The invention further provides methods of polishing a substrate comprising the use of the polishing pads and a method of producing the polishing pads.

Claims37

Dependent claims

A polishing pad for chemical-mechanical polishing comprising a pad body comprising a porous polymeric material, the pad body having at least one first region and at least one second region adjacent to the at least one first region, the pad body including pores having a first void volume in the at least one first region and pores having a second void volume in the at least one second region, wherein the pores in the at least one first region have a void volume of about 5% to about 50%, and the pores in the at least one second region have a void volume of about 20% to about 80%, and wherein the at least one first region or the at least one second region comprises about 5% or more closed cells, and wherein:

(a) the first void volume and second void volume are non-zero,
(b) the first void volume is less than the second void volume,
(c) the porous polymeric material in the at least one first region and the at least one second region has the same polymer formulation,
(d) the pad body does not have a structurally distinct boundary between the at least one first region and the at least one second region, and
(e) the pores in the at least one first region or the at least second region have a multi-modal pore size distribution, wherein the multi-modal distribution has about 20 or fewer pore size maxima.

2 more elements

Dependencies are inferred from the claim text.