Yamamoto Michitaka, Matsumae Takashi, Kurashima Yuichi, Takagi Hideki, Suga Tadatomo, Takamatsu Seiichi, Itoh Toshihiro, Higurashi Eiji
The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8563, Japan.
National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan.
Micromachines (Basel). 2020 Apr 27;11(5):454. doi: 10.3390/mi11050454.
Au-Au surface activated bonding (SAB) using ultrathin Au films is effective for room-temperature pressureless wafer bonding. This paper reports the effect of the film thickness (15-500 nm) and surface roughness (0.3-1.6 nm) on room-temperature pressureless wafer bonding and sealing. The root-mean-square surface roughness and grain size of sputtered Au thin films on Si and glass wafers increased with the film thickness. The bonded area was more than 85% of the total wafer area when the film thickness was 100 nm or less and decreased as the thickness increased. Room-temperature wafer-scale vacuum sealing was achieved when Au thin films with a thickness of 50 nm or less were used. These results suggest that Au-Au SAB using ultrathin Au films is useful in achieving room-temperature wafer-level hermetic and vacuum packaging of microelectromechanical systems and optoelectronic devices.
使用超薄金膜的金-金表面活化键合（SAB）对于室温无压晶圆键合是有效的。本文报道了膜厚（15 - 500纳米）和表面粗糙度（0.3 - 1.6纳米）对室温无压晶圆键合和密封的影响。硅和玻璃晶圆上溅射金薄膜的均方根表面粗糙度和晶粒尺寸随膜厚增加。当膜厚为100纳米或更小时，键合面积超过晶圆总面积的85%，且随着厚度增加而减小。当使用厚度为50纳米或更小的金薄膜时，实现了室温晶圆级真空密封。这些结果表明，使用超薄金膜的金-金SAB有助于实现微机电系统和光电器件的室温晶圆级气密和真空封装。
