Growth of antimonide compound semiconductor on Si(001) substrate

Abstract

We investigated the heteroepitaxial growth of GaSb on Si(001) substrates. High-quality GaSb films were grown on Si substrates by using an AlSb initiation layer. When small AlSb islands were formed on the Si substrate before the GaSb growth, two-dimensional GaSb film was grown. In contrast, without small AlSb islands, large GaSb islands formed on the substrate. Therefore, the AlSb islands played an important role in preventing excessive surface diffusion of Ga atoms on the Si surface and promoting two-dimensional growth of GaSb. A narrow X-ray diffraction rocking curve (around 200 arcsec) was obtained by optimizing the growth temperature and the thickness of the AlSb initiation layer. High-quality GaSb/AlGaSb and InGaSb/AlGaSb MQW samples were also grown on a Si substrate by using this method. At room temperature, these samples gave a strong emission at 1.55 μm, which is a wavelength used by fiber optic communications systems. Furthermore, we could control the emission wavelength by simply changing the well width. The emission energy was in good agreement with the theoretical curve. The temperature dependence of the PL intensity indicated a large activation energy (~77.6 meV) from the GaSb QWs. These results indicate that the fabricated QW structure had high crystalline quality and that GaSb quantum wells can be fabricated on Si for optical devices operating above room temperature.