The Effect of Pad Groove Density on CMP Characteristics

패드 그루브의 밀도변화가 연마특성에 미치는 영향

  • 박기현 (부산대학교 정밀기계공학과) ;
  • 정재우 (부산대학교 정밀기계공학과) ;
  • 이현섭 (부산대학교 정밀기계공학과) ;
  • 서헌덕 (부산대학교 정밀기계공학과) ;
  • 정석훈 (부산대학교 정밀기계공학과) ;
  • 이상직 (부산대학교 정밀기계공학과) ;
  • 정해도 (부산대학교 기계공학부)
  • Published : 2005.08.01

Abstract

Polishing pads play an important role in chemical mechanical polishing(CMP) which has recently been recognized at the most effective method to achieve global planarization. In this paper, we have investigated CMP characteristics as a change of groove density of polishing pads. The parameter $(K_n)$ is proposed to estimate groove density of pad. The $K_n$ is defined as groove area divided by pitch area. As the groove density value increased, removal rate increased to some point and then gradually saturated in case of increasing the groove density excessively. In addition Within wafer non-uniformity(WIWNU) worse as groove density increased excessively, although WIWNU improved as groove density increased. Also the uniformity of temperature of pad surface decreased as the groove density increased. It was because that the cooling effect increased as groove density increased. In other words, increasing the groove density which means the apparent contact area of pad has influence on amount of discharge of slurry during polishing process.

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References

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