Al-Al thermocompression bonding for wafer-level MEMS sealing
Al-Al thermocompression bonding for wafer-level MEMS sealing
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DOI：
10.1016/j.sna.2014.02.030
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发表时间：
2014-05-01
影响因子：
4.6
通讯作者：
Finstad, T. G.
中科院分区：
文献类型：
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作者：
Malik, N.;Schjolberg-Henriksen, K.;Finstad, T. G.
利用MEMS器件圆片级密封相关的测试结构对Al-Al热压键合进行了研究。将具有突出框架结构的Si晶片键合到平面Si晶片，两者都覆盖有1 μ m厚的溅射Al膜。不同的键合工艺变量是键合温度（400、450和550 ℃）和键合力（18、36和60 kN）。框架宽度为100 μ m，200 μ m，采用圆角或尖角框架。粘合后，将层压材料切成单片并进行拉伸测试。系统地研究了工艺和设计参数对切割产率、粘结强度和所得断裂表面的影响。对于所有三种粘结力，在450 ° C或以上的粘结或在400 ° C下用60 kN粘结力的粘结，测试结构显示出20-50 MPa的平均强度。目前的研究表明，强的Al-Al热压结合可以在450 ℃或以上的结合温度下实现低（18 kN）和中等（36 kN）的结合力，或者在400 ℃下通过高结合力（60 kN）实现。结果表明，在所研究的温度范围内，Al-Al热压焊需要增加键合力来补偿降低的键合温度。(C)2014爱思唯尔有限公司版权所有。
Al-Al thermocompression bonding has been studied using test structures relevant for wafer level sealing of MEMS devices. Si wafers with protruding frame structures were bonded to planar Si wafers, both covered with a sputtered Al film of 1 mu m thickness. The varied bonding process variables were the bonding temperature (400, 450 and 550 degrees C) and the bonding force (18,36 and 60 kN). Frame widths 100 mu m, 200 mu m, with rounded or sharp frame corners were used. After bonding, laminates were diced into single chips and pull tested. The effect of process and design parameters was studied systematically with respect to dicing yield, bond strength and resulting fractured surfaces. The test structures showed an average strength of 20-50 MPa for bonding at or above 450 degrees C for all three bonding forces or bonding at 400 degrees C with 60 kN bond force. The current study indicates that strong Al-Al thermocompression bonds can be achieved either at or above 450 degrees C bonding temperature for low (18 kN) and medium (36 kN) bond force or by high bond force (60 kN) at 400 degrees C. The results show that an increased bond force is required to compensate for a reduced bonding temperature for Al-Al thermocompression bonding in the studied temperature regime. (C) 2014 Elsevier B.V. All rights reserved.