直接键合InP-GaAs结构界面的特性研究

Study on infrared absorption of interfaces in direct wafer bonded InP-GaAs structures

通过对直接键合InPGaAs结构的红外吸收光谱分析以及断面扫描电子显微镜观察发现,样品制备过程中不均匀的外加压强导致InPGaAs交界面局部出现了不连续过渡的空间层,实验上将熔融石蜡渗透并被填充到该空间层,利用其对3.509μm波长光的强烈吸收特性可表征这种局部的键合不连续区域,二维扫描测试样品不同区域的吸收谱得到3.509μm波长吸收强度等值线图,从而描绘出外加压强的不均匀分布.实验上通过改进键合装置的施压均匀性,得到了连续过渡界面且均匀键合的InPGaAs结构,利用这种均匀键合技术有望制备大尺寸器件例如光学微腔等.

Direct wafer bonded InP-GaAs structures are studied by FTIR infrared absorbance spectra and FESEM cross-sectional observations. Experiments show that the non - uniformity of bonding pressure during the fabricating step results in the appearance of a spacer-layer at the InP-GaAs interface. By melting wax and filling it into this spacer-layer, locally unbonded areas can be characterized upon the optical absorbance peaks at 3. 509 μm. The 3. 509μm absorbance-intensity mapping images the nonuniform distribution of bonding pressure, which was obtained by two-dimensionally scanning measurement of infrared spectra of samples. Uniformly bonded InP-GaAs structures with uninterrupted interface are fabricated after improving the uniformity of pressure of fixture, which will be prospect of preparing for large scale wafer bonding structures such as optical micro-cavity structures.