A 1 nA current reference circuit is designed in semiconductor laboratory (SCL) 0.18 μm standard threshold voltage CMOS technology under 1.8 V power supply. The reference current is extremely immune to supply variation and shows a line sensitivity of 0.002%/V at post layout simulation level, over a wide range of supply variation from 0.5 V to 3.5 V. The line sensitivity is much smaller than any relevant data so far reported. In addition, it has a very low temperature coefficient of 214 ppm/°C over a temperature variation from −50°C to 50°C. The circuit consumes a total power of 588 nW. The reported results are also studied at various process corners and under variable process parameters like oxide thickness and threshold voltage of transistors. A satisfactory behaviour of the circuit is obtained in all cases. The accuracy of the simulation results is validated through quite close matching of the results with that obtained through rigorously developed theoretical models.

The Kagome antiferromagnet Mn3Sn has garnered much attention due to the presence of exciting properties such as anomalous Hall and Nernst effects. This paper discusses the synthesis of crystalline Mn3Sn thin films, prepared on Al2O3 (0001) substrates at 453±5°C using molecular beam epitaxy. The growth is monitored in situ using reflection high energy electron diffraction and measured ex situ using x-ray diffraction, Rutherford back-scattering, and cross-sectional scanning transmission electron microscopy. Our analysis shows the in-plane lattice constants of a1,M=4.117±0.027 Å and a2,M=4.943±0.033 Å, which is a very unexpected result when compared to the bulk a-plane Mn3Sn. This indicates a strain in the film and makes it challenging to provide a straightforward explanation. In an effort to explain our results, we discuss two possible orientation relationships between the Mn3Sn films and the sapphire substrates. Samples prepared under these conditions appear to have smooth surfaces locally, but overall the film has a 3D island morphology. First-principles calculations provide atomic models of the Mn3Sn (112¯0) lattice on Al2O3 (0001) high symmetry sites, indicating that the L3-R90° is the most stable configuration. A detailed discussion of the experimental data and theoretical results, as well as strain effects, is provided.

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