Chemical vapor deposition (CVD) has proven its surpassing advantages, such as larger scale, interlayer orientation control and clean interface, in the synthesis of transitional metal dichalcogenide (TMDC) semiconductor/semiconductor van der Waals (vdW) heterostructures. However, it is suffering problems of high melting points and low chemical reactivity of metal oxide feedstocks in the preparation of high-quality metal/semiconductor (M/S) TMDC vdW heterostructures. Here, for the first time, we report the synthesis of the M/S TMDC vdW heterostructure NbS2/MoS2 via a one-step hailde-assisted CVD method, which effectively overcomes the drawbacks of metal oxide precursors. What's more, this one-step method provides the high quality and clean interface of the NbS2/MoS2 heterostructure, which has been proved by the transmission electron microscopy characterization. A mechanism that MoS2 finishes the growth first and subsequently serves as a superior substrate for the growth of NbS2 is proposed. This novel method will open up new opportunities in the syntheses of other M/S TMDC vdW heterostructures and facilitate the research of the TMDC M/S interface.

The authors report on the optical properties of nanocrystalline ZnO grown at 200°C by radio-frequency magnetron sputtering. The nanocrystalline nature of the films was confirmed by cross-sectional transmission electron microscopy. In these films, ZnO nanocrystals with an average size of about 3–5nm were embedded in an amorphous matrix. The photoluminescence spectra from such nanostructured thin films show the near-band-edge emissions around 3.3eV. A redshift of about 8–11cm−1 is observed in the case of first-order longitudinal-optical (LO) phonon of ZnO in such nanostructures when compared to the LO phonon peak of bulk ZnO. The ultraviolet resonant Raman excitation at 77K shows multiphonon LO modes up to eighth order.

Metal/two-dimensional carbon junctions are characterized by using a nanoprobe in an ultrahigh vacuum environment. Significant differences were found in bias voltage (V) dependence of differential conductance (dI/dV) between edge-and side-contact; the former exhibits a clear linear relationship (i.e., dI/dV ∝ V), whereas the latter is characterized by a nonlinear dependence, dI/dV ∝ V 3/2 . Theoretical calculations confirm the experimental results, which are due to the robust two-dimensional nature of the carbon materials under study. Our work demonstrates the importance of contact geometry in graphene-based electronic devices.

Recently, we have developed a spin Hall magnetoresistance (SMR) sensor using the spin–orbit torque effective field as the built-in linearization mechanism, which allows us to achieve a linear, zero-offset, and low-noise magnetic field sensor without any dedicated magnetic bias. In this work, we examine the response of the SMR sensor to a time-varying magnetic field and demonstrate that its inherent frequency selectivity makes it uniquely suited for applications in eddy current testing. By applying a square wave current to both the coil and the sensor, and with the help of principal component analysis, we show that it is possible to detect surface cracks on an aluminum plate with dimensions down to 0.2 mm, without the need to use any sophisticated detection circuitry.

Discolored bondpads & non-stick failure in 0.6 μm wafer fab process with the hot Al alloy metallization was investigated. SEM, EDX & AES techniques were used to identify the root causes. Failure analysis results showed that discolored bondpads & non-stick failure were caused by TiN residue introduced during L95 bondpad opening wafer fab process. TiN residue on bondpad might have led to non-stick bondpad issue. The results also showed that it was difficult to determine the trace amount of TiN residue on bondpad using EDX technique due to its limitations. In this work, Auger surface analysis technique was used to determine TiN residue on bondpads with Al/TiW/Ti metallization. Auger results showed that Ti & N peaks were detected on discolored bondpads. It has resulted in non-stick bondpad failure. The solution to eliminate TiN residue on bondpads was to increase etch time at L95 bondpad opening wafer fab process. After using the new recipe with longer etch time, Auger results on the bondpads showed that no Ti & N peaks were detected and the bond-pull testing also passed.