Via Cleaning Process for Laser TSV process

Laser TSV 공정에 있어서 Via 세정에 관한 연구

  • Seo, Won (Department of Electronic Engineering, Kangnam University) ;
  • Park, Jae-Hyun (Department of Electronic Engineering, Kangnam University) ;
  • Lee, Ji-Young (Department of Electronic Engineering, Kangnam University) ;
  • Cho, Min-Kyo (EPSystem Co. Ltd.) ;
  • Kim, Gu-Sung (Department of Electronic Engineering, Kangnam University)
  • Published : 2009.03.30

Abstract

By Laser Through-Silicon-Via process, debris and particles occur when you are forming. Therefore the research of TSV cleaning become important to remove those particles and debris. Both chemical cleaning method that uses a surfactant and physical cleaning method that uses a brush were studied with the via of $30{\mu}m$ diameter and $100{\mu}m$ depth on the 8 inch CMOS Image Sensor wafer. On the DI water and a surfactant in mixture ratio of 2:1, debris show $73{\mu}m^2$ per $0.054mm^2$. Cleaning is superior by lower mixture ratio of DI water and surfactant. In addition, It is less than 5% of debris distribution in the laser condition changed by Laser's frequency and its speed and cleaning had no effect. In the physical cleaning, there are no crack and damage when the system condition is set by $1000{\sim}3000rpm$ strip, $50{\sim}3000rpm$ rinsing, and $200{\sim}300rpm$ brushing Therefore, debris and particles can be removed by enforced chemical method and physical method.

레이저를 이용 실리콘 관통형 접속기술인 TSV(Through-Silicon-Via)를 형성할 경우 Debris(파편물) 및 Particle이 발생되므로 이를 제거하기 위한 세정공정을 연구하였다. 계면활성제를 이용한 화학적 세정과 Brush를 이용한 물리적 세정을 검토하기 위하여 세정기를 제작하고 8인치 CMOS Image Sensor wafer에 직경 $30{\mu}m$, 깊이 $100{\mu}m$를 갖는 Via를 제작하여 두 가지의 세정방법을 연구하였다. 세정액은 DI Water와 계면활성제의 혼합비 2:1에서 Debris 범위가 $73{\mu}m^2$로 희석비가 낮을수록 세정력이 우수하였다. 레이저의 주파수와 속도변위에 따른 가공 조건 변화에는 Debris 분포차가 5% 미만으로 세정력에는 영향이 없었다. Brush를 이용하여 Debris를 제거하는 실험에서 Strip $1000{\sim}3000rpm$, Rinse $50{\sim}3000rpm$, Brush $200{\sim}300rpm$ 으로 증가시켜 세정하였을 때 Crack이나 손상 없이 Debris의 분포가 감소하였다. 따라서 화학적 세정과 물리적 세정으로 Debris를 제거할 수 있다.

Keywords

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