웨이퍼 레이저 절단 가공성 향상을 위한 연구

Abstract

본 논문에서는, 반도체 공정 한부분인 웨이퍼 레이저 절단 공정의 성능 개선을 위한 연구가 제안된다. 정밀 웨이퍼 레이저 절단 방식은 내부에서 미세하게 개질층을 가공하는 방식으로 수 마이크로 가공영역 조절이 필요하다. 기계적인 특성상 열 변형에 의한 가공 편차가 발생하기에, 가공 축부 변위발생 및 공작물 이송장치의 구동오차에 의한 공구 위치변화 최소화 기술을 개발하여, 절단 방식 적용을 위한 가공 중에 의해 발생되는 불량크랙 생성의 최소화를 연구 목표로 기계적 5가지 사항에 대하여 실험 및 분석이 수행되었다. 첫 번째로 온도변화 적용 가공편차 평가를 통하여 온도영향에 따른 가공 편차 값을 확인하였다. 두 번째로 Granite bridge의 구조 해석을 통한 전체 구조물에 안전성 평가 확인하였다. 세 번째로 가공 축 내부 온도 측정 동작 전후 온도를 비교하였다. 네 번째 가공 축 열 구조 해석을 통한 강성 및 열 변화를 확인하였다. 다섯 번째로 실제 온도에 따른 가공 축 변화 및 처짐 방향을 분석하였다. 이상 다섯 가지 분석사항을 통하여 기계적인 원인을 확인하여 가공기의 구조를 개선설계 하였다. 마지막으로, 실시간 가공축 자세 보정을 통하여 목표한 편차로 가공성능이 향상되었다.|In this paper, a study to improve the performance of laser cutting process for semiconductor wafer is presented. The precision laser cutting process of wafer requires manipulating the cutting area since the process cuts the reforming layers of an wafer. To improve the precision level of the cutting process, the tool positioning error and other errors sources related the heat are analyzed into five major components and the corresponding tests and analysis were implemented. First, the cutting position variation depending on the thermal error was analyzed. Second, structural analysis for the granite bridge was implemented for safety evaluation. Third, the inside temperatures of the processing axis of before and after the process were compared. Fourth, a thermal-structural analysis for the processing axis to analyze the structure and the thermal deformation was done. Fifth, the deformation direction by the actual temperature was analyzed. From the five analysis results, the design of the cutting machine has been improved. Finally, the cutting error has been more decreased into the targeted level by applying a real-time cutting position compensation technology.; In this paper, a study to improve the performance of laser cutting process for semiconductor wafer is presented. The precision laser cutting process of wafer requires manipulating the cutting area since the process cuts the reforming layers of an wafer. To improve the precision level of the cutting process, the tool positioning error and other errors sources related the heat are analyzed into five major components and the corresponding tests and analysis were implemented. First, the cutting position variation depending on the thermal error was analyzed. Second, structural analysis for the granite bridge was implemented for safety evaluation. Third, the inside temperatures of the processing axis of before and after the process were compared. Fourth, a thermal-structural analysis for the processing axis to analyze the structure and the thermal deformation was done. Fifth, the deformation direction by the actual temperature was analyzed. From the five analysis results, the design of the cutting machine has been improved. Finally, the cutting error has been more decreased into the targeted level by applying a real-time cutting position compensation technology.