Massively Parallel Optical Interconnection for Realization of Three-Dimensional Integrated Circuits

为了实现三维集成电路，在工作在小电流下的硅集成电路上制作小型光学器件是必不可少的。首先，我们尝试在硅衬底上生长高质量的GaP层作为初始层。采用迁移增强外延技术(MEE)在生长初期抑制了层错的产生，在Si衬底的GaP层上生长了InGaP/GaAs双异质结构的发光二极管，获得了正常的自发辐射，然后在氢原子辐照下，在覆盖有高质量的干式SiO_2掩膜的Si衬底上选择性地生长了GaAs。当选择性生长初始GaP层时，通过低温在Si衬底表面形成一层P-preayr，防止了反相畴向表面的扩展。研究还发现，通过插入MEE生长的应变短周期超晶格(SSPs)，在GaAs选择外延层中降低了线位错密度。此外，在具有晶格弛豫的异质界面处引入的失配位错被H原子辐照电钝化。这一结果可用于制造高质量和高可靠性的小型光学器件，用于层叠硅集成电路之间的大规模并行光互连。

It is essential to fabricate small optical device on Si integrated circuits, which operate under small current, for realization of three-dimensional integrated circuits. Firstly, we attempted to grow a high quality Gap layr as the initial layr on Si substrates. The generation of stacking faults was suppressed at the initial growth stage using the migration-enhanced epitaxy (MEE).The normal spontaneous emission was obtained from a InGaP/GaAs double-hetero structure light emitting diode grown on the GaP layr on Si substrate.Then, we performed the selective growth of GaAs on Si substrate covered with a high quality dry-SiO_2 mask under atomic hydrogen (H) irradiation. The propagation of anti-phase domains to the surface was prevented by forming a P-prelayr at low temperature on the surface of Si substrate when the initial GaP layr was selectively grown. It was also found that the density of threading dislocations was reduced in a GaAs selective epitaxial layr by inserting strained short-period superlattices (SSPSs) grown by MEE.Moreover, it appeared that misfit dislocations introduced at the heterointerface with lattice relaxation were electrically passivated by atomic H irradiation.These results can be applied to the fabrication of small optical devices with high quality and reliability for massively parallel optical interconnection among stacked Si integrated circuits.