Researches On Electrical And Mechanical Characteristics Of Low Temperature InP/Si Wafer Bonding

The researches in this thesis are supported by grants from the National Basic Research Program of China(No.2003CB314902) and the project of the National Natural Science Foundation of China(No: 60576018).With the rapid development of information technology, the need for large capability, high-speed transmission and management becomes more and more urgent. Substituting photon for electron to realize high-speed interconnection becomes a new tendency. The development of optical integration or optoelectronic integration will push information technology to a new period. With the development of optoelectronic technology, the size of devices is smaller and smaller, while the performance is more and more excellent. Therefore, the integration of devices with heterogeneous materials on a single chip has become a new hotspot in the field of optoelectronic devices. However, breaking through the limitation of integrating heterogeneous materials is the prerequisite for devices integration.A new integration technology named "Wafer bonding technology" has been developed in recent years. The technology can integrate different materials and provide the possibility to combine their advantages. It greatly improved the flexibility of device design and the performance of devices. Therefore it has been used in many fields, including optoelectronic devices, micro-electronic circuits, sensors, power devices and micro-machine process. In this thesis, a great deal of research work can be described as follow: wafer bonding technology was introduced and researched; the theories about low temperature InP/Si wafer bonding were investigated and the experiments were carried out. The main work can be summarized as follows: 1. Based on the DMT theory, the real area of contact between two wafers and effective wafer bonding energy of InP/Si were calculated and the results were analyzed. The effect of macro-scale wafer bow and micro-scale wafer waviness on the interface of InP/Si bonded wafers was analyzed with the linear elastic thin plate theory.2. The thermal stress arising from wafer bonding was analyzed; the physical model was established and the distribution characteristics curves of the shearing stress and normal stress were obtained. These results indicated that the shearing stress at the interface reaches the maximum at the edge of the wafer and declines with the increase of the distance from the edge, while the normal stress at the interface reaches the maximum at the center of the wafer and declines to zero with the increase of the distance from the center.3. The capacitance, voltage and current characteristics of n-InP/n-Si heterojunction were analyzed in detail according to the correlation theories of heterojunction electrical characteristics. The I-V curves of n-InP/n-Si were obtained under two different theoretical models.4. Participated in the experiment of the low temperature (270°C) InP/Si wafer bonding and tested the I-V characteristics of n-InP/n-Si homojunction. Based on the same processes, a DBR epitaxial wafer was bonded to a silicon substrate successfully. Then the transmission spectrums of DBR epitaxial wafer before and after bonding were contrasted and analyzed.