标题: | 砷化镓与矽基板之金属接合技术研究及其在半导体雷射上的应用 FLIP-CHIP BONDING OF GaAs on Si SUBSTRATES AND ITS APPLICATION TO SEMICONDUCTOR LASERS |
作者: | 彭显智 PENG, SHENG-JIH 李建平 LEE CHIEN-PING 电子研究所 |
关键字: | 混成整合;金属接合;欧姆接触;半导体雷射;矽V形凹槽;面射;hybrid integration;flip-chip bonding;ohmic contact;semiconductor laser;Si V-groove;surface-emitting |
公开日期: | 1995 |
摘要: | 为增强单一基板的功能,不同材料间的混成整合已是一愈来愈重要的课 题. 最近的研究大多投入在基板直接整合技术上. 对flip-chip bonding 来说,使用具有多重优点的薄接合材料是一新的趋势. 在本篇论文中,我们 提出接合材料与元件欧姆接触的结合. 我们使用可分别作为n及p型砷化镓 欧姆金属的金锗及金铍合金. 另外,我们也尝试两边用不同材料(砷化镓用 金锗或金铍合金,矽用金)及在矽上用两层材料(金锗/金或金铍/金)的接 合. 首先藉由研究接合温度,时间及金属厚度对联结机械强度的效应,找 出最佳接合条件.为防止表面氧化,我们在几乎无氧的环境中进行接合,同 时对介面施以压力. 金锗合金的最佳接合条件为450~480 C八到十分钟,而 金铍合金则是600~630 C八到十分钟. 我们也观察到互相扩散所造成的接 合金属熔点上升. 接着,我们将GRIN-SCH-QW雷射与表面镀有不同金属的 矽基板---金锗,金,金锗/金与金锗细条/金进行接合. 我们得到和接合前 几乎相同的I-V曲线及接近的L-I特性,显示雷射特性和电性都得以维持. 与矽基板间通过联结与欧姆接触的电导通也建立得很好. 77K和70C间的热 冲击在30~35个周期内不会对电性造成衰减. 联结的机械强度也很好. 进 一步, 我们把雷射接合在蚀刻出来的矽V形凹槽中的金表面及金锗细条上. 凹槽的54.7度(111)平坦斜面是用来反射雷射光而达到面射的效果. 热和 机械性质都很好,I-V曲线维持正常特性,而L-I特性也具有和原来相当的起 始电流和量子效率. 这些都证明了这个技术能可靠地产生面射的雷射光, 且有良好的电性. For enhancement of functionality and performance on a single substrate, hybrid integration of dissimilar materials has been an issue with increasingimportance. Much effort has been devoted to direct wafer bonding approachesin recent researches. For flip-chip bonding, the trend of using thin bonding materials with many advantages is reported. In this thesis, we propose the combination of bonding materials with ohmic contacts for devices. We use AU-Ge and Au-Be alloys which are ohmic metals for n- and p-type GaAs respectively. On the other hand, bonding with different materials on both sides (Au-Ge or Au-Be on GaAs with Au on Si) by wetting of low surface energymaterials (alloys) and two layer materials on Si (Au-Ge on Au on Si or Au- Beon Au on Si) are also considered. The first work is to find the optimum bonding condition for each material system by investigating the effects of bonding temperature, bonding time andmetallization thickness. Bonding is proceeded in a nearly oxygen-free ambientpreventing oxide formation with a proper pressure applied to the interfacefacilitating the reaction. Bonding is best achieved at 450~480 C for 8~10 minfor Au-Ge and 600~630 C for 8~10 min for Au-Be. The effect of melting point rise caused by interdiffusion is also observed. Second, we integrate GRIN-SCH-QW lasers to different metallizations on Sisubstrates---Au-Ge, Au, Au-Ge on Au, Au-Ge stripes on Au. Nearly identicalI-V curves and similar L-I characteristics to pre-bonding conditions are obtained, showing maintained laser performance and electrical properties. Good electrical interconnection through the formed bonds and ohmic contacts is well established. Thermal shocks between 77K and 70C cause no I- V curvedegradation up to 30~35 cycles. Further, lasers are bonded to both Au surfaces and Au-Ge stripes in etched Si V- grooves with 54.7 degree (111) smooth surfaces as reflection mirrors to exhibit surface-emitting behavior. Good thermal and mechanical properties are achieved. I-V curves that remain normal and L-I curves with comparablethreshold currents and quantum efficiencies measured right above together prove that this bonding technique is reliable in producing surface- emitting performance of laser light with good electrical properties. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT840430061 http://hdl.handle.net/11536/60663 |
显示于类别: | Thesis |