Abstract: A method using tin as intermediate layer to bond aluminum-coated silicon wafers is researched. Compared with Al-Al direct thermo-compression bonding method, it provides a low temperature, low pressure and rapid wafer-bonding solution. The authors use 4-inch (100 mm) silicon wafers for the bonding experiment. A 500 nm-thick Al layer is sputtered onto the wafers. The wafers are then annealed in N₂ ambient at 450°C for 30 minutes. Next, in situ Ar plasma sputter cleaning is performed followed by a 500 nm-thick tin layer deposition onto the aluminum layer. After that, the wafer pairs are loaded into a vacuum bonder. Average shear strength of 9.9 MPa is achieved after bonding for 3 minutes. With the increase of bonding time, the shear strength decreases significantly.

Key words: wafer-level bonding, low temperature, low pressure, shear strength

摘要： 研究采用Sn作为中间层键合覆盖Al薄膜的硅片。相对于Al-Al直接热压键合, 该系统能提供低温、低压、快速的圆片级键合方案。采用直径为100 mm硅片, 溅射一层500 nm厚度的Al层后, 在N₂气氛下进行450°C, 30分钟退火, 采用Ar等离子体清洗后, 溅射一层500 nm厚度的Sn层。将硅片金属面紧贴在一起放入键合机中键合, 在真空中进行。键合时间为3分钟条件下, 得到平均剪切强度为9.9 MPa, 随着键合时间增加, 剪切强度显著降低。

关键词: 圆片级键合, 低温, 低压, 剪切强度