Studies on SiO2–SiO2 bonding with hydrofluoric acid. Room temperature and low stress bonding technique for MEMS
Studies on SiO2–SiO2 bonding with hydrofluoric acid. Room temperature and low stress bonding technique for MEMS
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DOI：
10.1016/s0924-4247(99)00246-0
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发表时间：
2000-02
影响因子：
4.6
通讯作者：
H. Nakanishi;T. Nishimoto;R. Nakamura;A. Yotsumoto;T. Yoshida;S. Shoji
中科院分区：
文献类型：
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作者：
H. Nakanishi;T. Nishimoto;R. Nakamura;A. Yotsumoto;T. Yoshida;S. Shoji
描述了 SiO2-SiO2 与氢氟酸 (HF) 键合的研究。该方法的显着特点是可以在室温下进行接合。该方法的优点是热损伤低、残余应力低、键合工艺简单，有望用于微机电系统（MEMS）的封装和组装。在HF浓度、施加压力、其他键合化学品等不同键合条件下测量了键合特性。粘合强度取决于粘合期间施加的压力。为了实现可靠的粘合，需要高于 0.5 wt.% 的 HF 浓度和 1.3 MPa 的大施加压力。使用 KOH 溶液代替 HF 也观察到了键合。应用透射电子显微镜（TEM）、二次离子质谱（SIMS）、放射性同位素（RI）分析和电子探针微量分析（EPMA）来评估键合界面。这些分析的结果表明，在键合的SiO 2 与SiO 2 之间形成包含氢和氟原子的氧化硅络合物的中间层。中间层的厚度很大程度上取决于粘合过程中施加的压力。当中间层较薄时，可获得较大的粘合强度。当两个表面的 SiO2 溶解在 HF 溶液中时，通过溶解的二氧化硅重新固化，在基材之间形成作为结合层的中间层，这是预期的结合机制。中间层的形成对于HF键合的特性起着非常重要的作用。
Studies on SiO2–SiO2bonding with hydrofluoric acid (HF) are described. This method has a remarkable feature that bonding can be obtained at room temperature. Advantages of this method are low thermal damage, low residual stress and simplicity of the bonding process, which are expected for the packaging and assembly of micro-electro-mechanical systems (MEMS). The bond characteristics were measured under different bonding conditions of HF concentration, applied pressure, another chemicals for bonding and so on. The bond strength depends on the applied pressure during bonding. To achieve reliable bonding, HF concentration of higher than 0.5 wt.% and a large applied pressure of 1.3 MPa are required. The bonding is also observed using KOH solution in stead of HF. Transmission electron microscopy (TEM), secondary ion mass spectrometry (SIMS), radioactive isotope (RI) analysis and electron probe micro analysis (EPMA) were applied to evaluate the bonded interface. The results of these analysis indicated that an interlayer of a silicon oxide complex including hydrogen and fluorine atoms is formed between bonded SiO2to SiO2. The thickness of the interlayer depends strongly on the applied pressure during bonding. Large bond strength is obtained when the interlayer is thin. The bonding mechanism is expected when the SiO2at both surfaces is dissolved in HF solution, and that the interlayer, which is a binding layer, is formed between substrates by resolidification of dissolved silicon dioxide. Formation of the interlayer plays very important roles for the characteristics of HF-bonding.