Al2O3/InSb/Si quantum well MOSFETs having an ultra-thin InSb layer
The fabrication and the properties of Al2O3-InSb-Si QW MOSFETs having an ultra thin InSb channel layer is reported. The good characteristic of ID-VD with an transconductance of 67 mS/mm demonstrates that the ultra thin InSb channel layer grown directly on Si can be used for MOSFET channels. The results show that the InSb/Si pseudomorphic quantum well MOSFETs is a promising candidate for future VLSIs.
Heteroepitaxial growth of rotated InSb films on a Si(1 1 1) substrate via 2×2-In surface reconstruction
Abstract The heteroepitaxial growth of InSb films via In-induced surface reconstructions such as 2×2-In and √3×√3-In on a Si(1 1 1) substrate was carried out by using a two-step growth procedure in an ultra-high vacuum (UHV) chamber. The samples were characterized by high-energy electron diffraction (RHEED), X-ray diffraction (XRD), scanning tunneling microscopy (STM) and Hall measurements. The RHEED and XRD ( φ scan) patterns of the samples showed the existence of InSb crystals rotated by 30° with respect to Si substrate. From comparison between the growth of InSb films via 2×2-In and that via √3×√3-In, we found that the origin of the 30°-rotated InSb is due to the existence of the In–Sb bi-layer formed by 1 monolayer (ML) Sb deposition onto the In-induced surface reconstructions.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.