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In this paper, AlN films grown by magnetron sputtering method have been proposed as the gate insulator layer of AlGaN/GaN high electron mobility transistors (HEMTs) to decrease gate leakage current and suppress the interface trap. The effect of the temperature of substrate on the quality of AlN films have been investigated. By inserting the thin AlN film (35 nm) as a gate insulator layer, the on-state resistance of AlGaN/GaN HEMTs decrease from 11.1 Ω mm to 10.3 Ω mm @ V g = 0 V, the current collapse decreases from 16.6% to 3.2%, the gate leakage can be reduced from 1.2 Ă— 10âˆ'1A mmâˆ'1 to 4.4 Ă— 10âˆ'6A mmâˆ'1 @ V g = 2 V by five orders of magnitude, and the fast interface states disappear and the normal trap density decreases from 0.96â€"1.3 Ă— 1013 cmâˆ'2eVâˆ'1 to 1.3â€"3.4 Ă— 1012 cmâˆ'2 eVâˆ'1, proving that magnetron-sputtered AlN is an effective way to improve the performance of GaN HEMTs. [ABSTRACT FROM AUTHOR]

To construct the Fas ligand (FasL) and inducible nitric oxide synthase (iNOS) coexpressed PCA13 plasmid used for packing of adenovirus, so as to observe the immunoprotective effect of FasL on the adenovirus vector. By way of the internal ribosome entry site (IRES), gene engineering techniques such as preparation and transformation of competent cells, plasmid extraction, agarose gel electrophoresis and restriction enzymolysis were used for the construction of the polycistron adenoviral expression vector PCA13/FasL–IRES–iNOS, which could coexpress FasL and the iNOS gene after multisubcloning steps. FasL and iNOS connected with the IRES were successfully cloned to the PCA13 plasmid and verified by enzymolysis (600 bp FasL, 1000 bp IRES and 4000 bp iNOS) and the gene sequence was concordant with the gene bank. The polycistron adenoviral expression vector PCA13/FasL–IRES–iNOS was successfully constructed. [ABSTRACT FROM AUTHOR]