A boron phosphide (BP) layer was grown on the (111) Si substrate by atmospheric pressure organometallic chemical vapor deposition (MOCVD) using triethylboran ((C 2 H 5 ) 3 B) and phosphine (PH 3 ) sources. By transmission electron diffraction analysis, the transparent BP layer was found to grow on (111) Si with the following orientation: (111),h110i-Si//(111),h110i-BP. The MOCVD-grown BP layers exhibited transparency under fluorescent light illumination. Reflected light color was observed to vary depending on the thickness of the BP layer. The refractive index (n) of the heteroepitaxial (111) BP layer was revealed to decrease from 3.16 at a wavelength () of 350 nm to 2.77 at of 750 nm. The extinction coefficient (k) corresponding to n at of 350 nm was 0.19. Refractive index (n) and k at of 350 nm gave 9.95 as the real part of the complex dielectric constant of the MOCVD-grown BP layer. The optical evaluation indicated that BP is applicable as a transparent III-V semiconductor layer for forming heteroepitaxial structures with Si.

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The crystallographic feature of a metal-organic CVD grown zinc-blende BP/wurtzite-GaN heterostructure was characterized utilizing high-resolution TEM and TED techniques. On the heterostructure system, the epitaxial relationship was revealed to be (0001), 〈a-axis〉-GaN//(111), 〈110〉-BP. (111)-BP was also found to be orientated in the "double positioning" with tracing hexagonal shape of (0001)-GaN probably because of the matching in the spacings between the a-axis of GaN (a = 0.319 nm) and the {110}-planes of BP (= 0.320 nm). (111)-BP was additionally recognized to stack in the c-direction of GaN with period of just half value of the c-axis (c = 0.518 nm). In addition to the matching property, (111)-BP joined with (0001)-GaN was found to be effective for annihilation of dislocations penetrating from the underneath GaN.1 Introduction Gallium nitride(GaN)-related semiconductors, such as gallium nitride (GaN) and indium nitride(InN), are attracting much attention as a promising material for high-brightness GaInN heterojunction light-emitting diodes (LEDs), GaInN/GaN double heterostructure (DH) laser diodes (LDs), high-frequency AlGaN/GaN heterojunction power FETs, etc. With an increasing technical demand to improve the performance of the GaN-based semiconductor devices, crystallographic characterization is required to clarify the influence of crystalline defects in the GaN-related material on the device performance. Advanced researches have been therefore done, for example, to study the effect of dislocations in the GaN for the improvement of light emission intensity of GaN-based LEDs [1]. According to the analysis based on the non-radiative carrier recombination model [1], the dislocation density in the GaNrelated material is recommended to reduce at least down to the order of 10 7 cm -2 to obtain a higher emission efficiency. Development of techniques for suppression of dislocations in the GaN-related materials becomes important to produce high-performance GaN-based LEDs and LDs. In addition to the traditional growth technique, recent techniques, such as ELO [2] and delta (δ)-doping of silicon (Si) impurity into GaN layer is recently proposed to annihilate threading screw dislocations for (111)-Si/GaN heterostrucure system [3].In this paper, boronphosphide (BP), one of the III-V compound semiconductors, is grown on GaN to form a lattice-matched heterojunction, and effective annihilation of the dislocation penetrating from underneath GaN by the heterojunction system is reported.

Formation of interfacial dislocations (IDs) and dislocation half-loop arrays (HLAs) and their appearance in 4H-SiC epi-wafers are investigated by X-ray topography and KOH etching analysis. Synchrotron reflection X-ray topography demonstrates the ability to image IDs and HLAs simultaneously and reveal their densities as well as spatial distributions in the epi-wafers. The vertical location of IDs in the epi-wafer is also examined by this technique. The influence of wafer warp, in-situ H2 etching prior to epitaxial growth, substrate off-angle as well as the growth face (Si-face and C-face) on the densities and spatial distributions of IDs and HLAs are discussed.

The production of 150 mm-diameter SiC epi-wafers is the key to the spread of SiC power devices. Besides, step-bunching free surface leads to high-performance devices. We have developed the production technology of the epitaxial growth with smooth surface morphology for 4º off Si-face 4H-SiC epitaxial layers on 150 mm diameter substrates. The various area observations of the surface by optical surface analyzer, confocal microscope and atomic force microscope revealed that there was no conventional step-bunching in whole wafer surface. While creating step-bunching free surface is more difficult for thicker epilayer growth, we have achieved step-bunching free surface for 30-μm thick epilayer on a 150 mm diameter substrate. The typical values of thickness uniformity of the 30μm-thick epilayer are 0.5% (σ/mean) and 1.7% (range/mean). A few interfacial dislocations (IDs) were detected for the 150 mm-diameter epi-wafer by reflection X-ray topography. We have succeeded in removal of IDs by the optimized growth condition.