The complex refractive index of silicon using terahertz-time domain spectroscopy (THz-TDS), with an InAs wafer under the influence of a magnetic field as emitter, has been studied. By applying a magnetic field on the InAs emitter, the detected temporal waveform broadens and the spectral weight of its Fourier spectrum shifts toward the low frequency region. Calculating the real (n) and imaginary (κ) parts of the complex refractive index of silicon, it is found that with the application of a magnetic field the plots of these quantities in the low frequency region (sub-terahertz region) are smoother than those without magnetic field. These features indicate that a significant enhancement of the signal-to-noise (S/N) ratio in the low frequency region can be obtained by applying a magnetic field on the InAs emitter.
Carbon-ion-implanted InAs was investigated using double-crystal x-ray diffraction (DCXRD), Hall measurement and infrared absorption (IR) analysis. Multiple implantation were made at 0.1–0.4 MeV with 6.0 × 1012–2.0 × 1013 ions cm−2. After rapid thermal annealing at 300 °C for 20 s, the implantation-induced damage was removed substantially, indicating the recovery of crystallinity. The results of Hall measurement reveal strong electrical compensation and low conductivity in the implanted layer of the sample, suggesting the formation of acceptor CAs. In contrast, the lowest IR transmittance is observed in the 300 °C annealed sample, implying the existence of acceptor with significant concentration. The implanted layer turned to n-type after annealing at 400 °C with the increasing transmittance. After annealing at temperature of 500 °C, the decreasing carrier concentration and the increasing transmittance is attributed to the competition between the decomposition of C–H complexes and the formation of donor centers C–C.
InAs-based interband cascade lasers (ICLs) with InAs plasmon waveguides or InAs/AlSb superlattice (SL) waveguides were demonstrated at emission wavelengths below 4.1 μm. The threshold current densities of the lasers with SL waveguides were 37 A/cm2 at 77 K in continuous wave mode. The operation temperature of these lasers reached room temperature in pulsed mode. Compared with the thick InAs n++ plasmon cladding layer, the InAs/AlSb superlattice cladding layers have greater advantages for ICLs with wavelengths less than 4 μm even in InAs based ICLs because in the short-wavelength region they have a higher confinement factor than InAs plasmon waveguides.
This paper demonstrates the fabrication of InAs-on-insulator (InAs-OI) structures with high crystallinity using the Smart Cut process, which combinates direct wafer bonding with a wafer splitting process by implanted H+. Controlling the implantation dose and rate allows us to produce wafer-level InAs-OI structures on Si substrates by H+ implantation at room temperature, which can be performed in standard implantation equipment. It is found that (111) InAs-OI has a much flatter surface after splitting than (100) one. After thinning by using CMP and wet etching, 15 nm thick InAs-OI structures are realized with the high thickness uniformity.