Patent ID: 6881134

Claim:
A carrier for supporting a microelectronic substrate relative to a planarizing medium during planarization of the microelectronic substrate, the carrier comprising: a support member; and a flexible, compressible membrane adjacent to the support member, the membrane having a first portion with a first thickness and a second portion with a second thickness greater than the first thickness, the membrane having a generally circular planform shape where the first and second portions of the membrane are annular with the first portion disposed radially inwardly from the second portion, the first portion of the membrane being aligned with a first part of the microelectronic substrate when the membrane engages the microelectronic substrate, the second portion of the membrane being aligned with a second part of the microelectronic substrate when the membrane engages the microelectronic substrate, the substrate directly contacting the membrane and being held stationary with respect to the membrane as the substrate is moved relative to the planarizing medium.