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We proposed a Si/III–V–N compound semiconductors/Si structure, which is applicable to optoelectronic integrated circuits (OEICs). The feature of this structure is that optoelectronic devices and Si electronic devices could be fabricated by low-temperature planar process at the same time. A dislocation-free and lattice-matched Si/GaP1−xNx/Si (x=2.9%) structure, which is a basic structure for OEICs, was grown by molecular-beam epitaxy. The images of transmission electron microscopy revealed that there were no threading dislocations and misfit dislocations in the epitaxial layers. It was clarified that the Si and GaP1−xNx layers were lattice-matched to Si and had structural high crystalline quality comparable to Si substrates.

We report that a lattice-matched and dislocation-free GaAsyP1−x−yNx/GaP0.98N0.02 quantum-well (QW) structure can be grown on a Si substrate. A two-dimensional growth mode was maintained during growth of all the layers. It was confirmed that the QW structure was lattice-matched to the Si substrate from the lattice constant measured by x-ray diffraction. A cross-sectional image taken by transmission electron microscopy revealed that no threading dislocations or misfit dislocations were observed at the QW structure.

The effect of rapid thermal annealing (RTA) on the luminescence properties of GaPN layers was investigated. GaPN layers were grown on GaP and Si substrates. The luminescence properties were evaluated by cathodeluminescence and low-temperature photoluminescence. It was found that the luminescence intensity was increased and the peak photon energy was shifted to the high-energy side in all samples after RTA. The luminescence intensity of the GaPN layers was increased with increasing the annealing temperature. It was also found that high-temperature RTA can be applied to the GaPN layer grown on the Si substrate with a thin Si cap layer rather than the GaPN layer on the GaP substrate. It was estimated that high-temperature RTA reduces the spatial fluctuation of nitrogen compositions and the density of defects attributed to nitrogen atoms. . Thus, GaPN has attracted much attention as a novel material, because GaPN with the nitrogen composition of about 2% is latticematched to Si. Moreover, relatively strong photoluminescence (PL) and electroluminescence have been observed [2,3]. We have realized a dislocation-free GaPN layer, which was lattice-matched to Si, grown on Si substrates with a thin GaP buffer layer [4,5]. Additionally, the PL was observed at room temperature (RT). However, the PL intensity was decreased with increasing the nitrogen composition as reported in previous papers [2,6]. The decrease in the PL intensity implies that the GaPN layer contains a large number of nonradiative recombination centers and/or deep-levels. These defects could be generated due to a large miscibility gap and fluctuations of nitrogen compositions in the GaPN layer. It is needed to improve the crystalline quality of GaPN layer.Thus, we have investigated the effect of rapid thermal annealing (RTA) on the luminescence properties of the GaPN layer grown on a GaP substrate (GaPN/GaP) and a Si substrate (GaPN/Si), respectively.

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