An in-depth analysis of gate stack enhancements that enable multi-Gb 3D NAND products is performed. Alternative charge trapping layer, enhanced tunnel oxide based on the VariOT concept and metal gate with Al2O3 high-k liner have been proposed and evaluated. The most promising solutions were successfully integrated in 3D devices. Integration challenges of the replacement gate approach, required to have metal gate in 3D NAND, are also analyzed and discussed in detail.

The atomic layer deposition (ALD) of Ta2O5 and TaSiOx from TaCl5, SiCl4, and H2O is reported. Both processes are influenced by the concomitant etching of Ta2O5 and TaSiOx by TaCl5. The optimum deposition temperature is found to be 250?degrees C for both Ta2O5 and TaSiOx. For lower deposition temperatures, the large Cl contamination leads to poor dielectric properties of the films, whereas higher temperatures lead to poor within-wafer (WiW) thickness non-uniformity due to etching. Si incorporation is limited to Si/(Si?+?Ta) similar to 0.65 because of the slow adsorption kinetics of SiCl4 on Si?OH-terminated surfaces. Under optimum conditions, amorphous films with good dielectric quality are obtained.

TaSiOx thin films with Si/(Ta+Si) mole fractions between 0 and 0.6 have been deposited using atomic-layer deposition on Si and InGaAs at 250^oC. Interface defects on InGaAs were on the order of 10^1^2cm^-^2eV^-^1, which is comparable to state-of-the-art Al2O3 deposited by atomic-layer deposition using Al(CH3)3 and H2O while the dielectric permittivity of TaSiOx is considerably higher.

There is an interest in the production of heat- and acid-stable enzymes due to their potential application in various industrial fields, particularly in the food, brewery, and textile industries. Microorganisms living in extreme habitats are a good source for such enzymes as they enable to perform biotransformation reactions under non-conventional conditions. After the complete genome analysis of the thermoacidophilic archaeon Picrophilus torridus (optimal growth at pH 0.7 and 60 degrees C) a number of genes were identified that encode for amylolytic enzymes, proteases, and esterases. A gene encoding an intracellular glucoamylase from P. torridus was cloned and successfully expressed in E. coli. The recombinant enzyme was purified to homogeneity with a yield of 37 % by heat treatment, anion exchange, and gel filtration chromatography. As revealed by non-denaturating PAGE, the active enzyme forms a homotetramer (73 kDa/subunit). The recombinant glucoamylase shows activity between 30 degrees C and 65 degrees C and a pH of between 4.5 and 6.5. Interestingly, the enzyme shows unique substrate specificity compared to already known glucoamylases. In addition to the hydrolysis of branched and linear alpha-glucans, the purified enzyme preferentially attacks maltotriose. The V-max for maltotriose (10 U/mg) is even higher than the V-max for starch (8 U/mg). The high maltotriose preference of this archaeal enzyme is unique among all glucoamylases described so far.

The euryarchaea Picrophilus torridus and Picrophilus oshimae are able to grow around pH 0 at up to 65°C, thus they represent the most thermoacidophilic organisms known. Several features that may contribute to the thermoacidophilic survival strategy of P. torridus were deduced from analysis of its 1.55-megabase genome. P. torridus has the smallest genome among nonparasitic aerobic microorganisms growing on organic substrates and simultaneously the highest coding density among thermoacidophiles. An exceptionally high ratio of secondary over ATP-consuming primary transport systems demonstrates that the high proton concentration in the surrounding medium is extensively used for transport processes. Certain genes that may be particularly supportive for the extreme lifestyle of P. torridus appear to have been internalized into the genome of the Picrophilus lineage by horizontal gene transfer from crenarchaea and bacteria. Finally, it is noteworthy that the thermoacidophiles from phylogenetically distant branches of the Archaea apparently share an unexpectedly large pool of genes.

AbstractDurch Erhitzen entsprechender Oxidmischungen wurden die farblosen Verbindungen LiScO2 und NaScO2 neu dargestellt. In der Struktur entspricht LiScO2 nach Pulver‐ und Einkristalluntersuchungen dem α‐LiFeO2‐Typ, der zur Raumgruppe 141/amd–D [a = 4,191 Å, c = 9,282 Å, c/a = 2,215; 4 Sc in (4a); 4 Li in 4(b); 8 O in 8(e) mit zO = 0,226; drö = 3,42 und dpyk = 3,42 g · cm−3] gehören soll, was nach der vorliegenden Untersuchung wahrscheinlich, aber noch nicht endgültig gesichert erscheint. NaScO2 gehört zum hexagonalen α‐NaFeO2‐Typ [a = 3,166 Å, c = 16,27 Å, c/a = 5,138, Z = 3 Formeleinheiten pro hexagonaler Elementarzelle, drö = 3,52 und dpyk = 3,41 g · cm−3].

Darstellung und Eigenschaften der bislang unbekannten Verbindungen LiInO 2 und NaInO 2 werden mitgeteilt. Beide sind farblos; mit Wasser tritt Hydrolyse ein. LiInO 2 kristallisiert wie α‐LiFeO 2 tetragonal mit a = 4,30 7 kX, c = 9,32 9 kX. NaInO 2 ist dem α‐NaFeO 2 isotyp; die Gitterkonstanten sind a hex = 3,22 9 kX, c hex = 16,3 2 kX.