MEMS 패키징용 hollow Cu 비아의 형성거동을 분석하기 위해, 펄스-역펄스 전류밀도 및 도금시간에 따른 hollow Cu 비아의 미세구조를 관찰하고 평균 두께 및 두께 편차를 측정하였다. 펄스-역펄스 전류밀도를 $-5;mA/cm^2$와 $15;mA/cm^2$로 유지하며 3시간 도금시 hollow Cu 비아의 평균 도금두께는 $5;{mu}m$이었으며 표준편차는 $0.63;{mu}m$이었다. 도금시간을 6시간으로 증가시 평균 도금두께는 $10;{mu}m$, 표준편차는 $1;{mu}m$로 균일한 두께의 hollow Cu 비아를 형성하는 것이 가능하였다. 펄스-역펄스 전류밀도를 $-10;mA/cm^2$와 $30;mA/cm^2$ 이상으로 증가시킨 경우에는 도금시간 증가에 따라 도금두께보다 도금두께의 표준편차가 더 크게 증가하여 균일한 hollow Cu 비아의 형성이 어려웠다.
In order to investigate the formation behavior of hollow Cu via for MEMS packaging, we observed the microstructure of the Cu vias and measured the average thickness and the thickness deviation with variations of pulse-reverse pulse current density and electrodeposition time. With electrodeposition for 3 hours at the pulse and reverse pulse current densities of $-5;mA/cm^2$ and $15;mA/cm^2$, the average thickness and the thickness deviation of the Cu vias were $5;{mu}m$ and $0.63;{mu}m$, respectively. With increasing the electrodeposition time to 6 hours, it was possible to form the Cu vias, of which the average thickness and thickness variation of the Cu vias were $10;{mu}m$ and $1;{mu}m$, respectively. With increasing the pulse and reverse pulse current densities to $-10;mA/cm^2$ and $30;mA/cm^2$, Cu vias of uniform thickness could not be formed due to the faster increase of the thickness deviation than that of the average thickness with increasing the electrodeposition time.
