Crystal growth of Sb-based compound semiconductors and jissoprocess for high-speed device circuits

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We have investigated lattice-mismatched growth of narrow-gap III-V compound semiconductors using molecular beam epitaxy. As results, we have elucidated their basic physical properties, including behavior of crystalline defects. For graded-buffer growth methods, there are both cases in which the method is effective and ineffective to reduce the defect densities, owing to the influence of alloy hardening. In the case of InAs grown on GaAs(001), the graded-buffer growth is not effective to reduce the defect density beyond the dislocation pair-annihilation mechanisms. In the case of In(Ga)Sb on GaAs(001), the threading dislocations limit the electron transport because they are the origin of the residual donors; lower local donor concentrations and higher local electron mobilities are obtained in regions with longer distances from the In (Ga)Sb/GaAs interface according to the pair-annihilation of the dislocations. In the case of heterostructures of the InGaSb channel and the InAlSb barrier … More on GaAs(001), we obtained two-dimensional electron gases (2DEGs) with very high electron mobilities, such as 30000cm^2/V-s at room temperature and 130000cm^2/V-s at low temperatures, as a result of the reduction of the dislocation density by employing thick InAlSb buffers with several micrometers thickness. The 2DEGs exhibit isotropic electron transport properties in spite of anisotropic stacking faults. Moreover, we observed an interplay between the Rashba and Dresselhaus spin-orbit interactions.We have also investigated epitaxial-lift off (ELO) and van der Waals bonding (VWB) processes of As-based narrow gap semiconductors for the high-speed device circuit jisso. We have successfully realized the ELO-VWB of narrow gap InGaAs/InAlAs metamorphic heterostructures by using selective etching of AlAs nano-sacrificial layers. This is the first realization of ELO-VWB for the metamorphic systems. The obtained devices on ceramic or Si substrates exhibit very high electron mobilities, such as 11000cm^2/V-s at room temperature, which is the highest ever reported for ELO-VWB devices. Our results show new possibilities of heterogeneous integration of narrow-gap semiconductor devices using lattice-mismatched growth. Less