磁気軸受制御型研磨ヘッドによるCMPの均一性向上
2004 年 70 巻 691 号 p. 855-860
詳細
2004 年 70 巻 691 号 p. 855-860
Magnetic bearing technology is applied to a CMP wafer carrier to control the polish rate profile by tilting the wafer carrier during polishing. If no control is applied, the wafer carrier subsides slightly into the pad and is tilted 18×10-5 rad by the viscoelasticity of the pad. The polish rate in the wafer outer area can be increased by tilting the carrier to the positive side; the polish rate of the wafer center area can be reduced by tilting it to the negative side. Constant current control leads to better control of the polish rate profile than feedback control. It has been reported to be possible to improve the polish rate profile by keeping the wafer carrier in a horizontal position using a magnetic control.
