Patent ID: 6869345

Claim:
An apparatus for planarizing a microelectronic substrate, comprising: a planarizing medium support; a planarizing medium supported by the planarizing medium support; a first substrate carrier positioned proximate to the planarizing medium, the first substrate carrier including a flexible, compressible first membrane having a first portion with a first thickness and a second portion with a second thickness different than the first thickness, a ratio of the first thickness to the second thickness having a first value, the first portion being aligned with a first part of the microelectronic substrate when the first membrane engages the microelectronic substrate, the second portion being aligned with a second part of the microelectronic substrate when the first membrane engages the microelectronic substrate; and a second substrate carrier positioned proximate to the planarizing medium, the second substrate carrier including a flexible, compressible second membrane having a first portion with a first thickness and a second portion with a second thickness different than the first thickness, a ratio of the first thickness to the second thickness having a second value different than the first value, the first portion being aligned with a first part of the microelectronic substrate when the second membrane engages the microelectronic substrate, the second portion being aligned with a second part of the microelectronic substrate when the second membrane engages the microelectronic substrate.