실리콘기판과 불소부식에 표면에서 금속불순물의 제거

• 영문명: Removal of Metallic Impurity at Interface of Silicon Wafer and Fluorine Etchant
• 발행기관: 한국응용과학기술학회 (구.한국유화학회)
• 저자명: 곽광수(Kwack, Kwang-Soo) 연영흠(Yoen, Young-Heum) 최성옥(Choi, Seung-Ok) 정노희(Jeong, Noh-Hee) 남기대(Nam, Ki-Dae)
• 간행물 정보: 『한국응용과학기술학회지』한국유화학회지 제16권 제1호, 33~40쪽, 전체 8쪽
• 주제분류: 공학 > 화학공학
• 파일형태: PDF
• 발행일자: 1999.03.30

영문 초록

We used Cu as a representative of metals to be directly adsorbed on the bare Si surface and studied its removal DHF, DHF-$H_2O_2$ 수식 이미지 and BHF solution. It has been found that Cu ion in DHF adheres on every Si wafer surface that we used in our study (n, p, n+, p+) especially on the n+-Si surface. The DHF-$H_2O_2$ 수식 이미지 solution is found to be effective in removing metals featuring high electronegativity such as Cu from the p-Si and n-Si wafers. Even when the DHF-$H_2O_2$ 수식 이미지 solution has Cu ions at the concentration of 1ppm, the solution is found effective in cleaning the wafer. In the case the n+-Si and p+-Si wafers, however, their surfaces get contaminated with Cu When Cu ion of 10ppb remains in the DHF-$H_2O_2$ 수식 이미지 solution. When BHF is used, Cu in BHF is more likely to contaminate the n+-Si wafer. It is also revealed that the surfactant added to BHF improve wettability onto p-Si, n-Si and p+-Si wafer surface. This effect of the surfactant, however, is not observed on the n+-Si wafer and is increased when it is immersed in the DHF-$H_2O_2$ 수식 이미지 solution for 10min. The rate of the metallic contamination on the n+-Si wafer is found to be much higher than on the other Si wafers. In order to suppress the metallic contamination on every type of Si surface below 1010atoms/cm2, the metallic concentration in ultra pure water and high-purity DHF which is employed at the final stage of the cleaning process must be lowered below the part per trillion level. The DHF-$H_2O_2$ 수식 이미지 solution, however, degrades surface roughness on the substrate with the n+ and p+ surfaces. In order to remove metallic impurities on these surfaces, there is no choice at present but to use the $NH_4OH-H_2O_2-H_2O$ 수식 이미지 and $HCl-H_2O_2-H_2O$ 수식 이미지 cleaning.