We describe studies of magnetotransport in antidot arrays formed by focused ion-beam implantation... more We describe studies of magnetotransport in antidot arrays formed by focused ion-beam implantation. This shows the dominant role played by interconnects between dotlike reservoirs. Two separate Shubnikovde Haas periodicities are observed at high and low fields, which allow separate measurements of the depth of the reservoirs and the interconnects. A large negative rnagnetoresistance is observed at low fields, which is interpreted as being due to the formation of propagating edge states as the field increases.
An x-ray zone plate was fabricated using the novel approach of focused ion beam (FIB) milling. Th... more An x-ray zone plate was fabricated using the novel approach of focused ion beam (FIB) milling. The FIB technique was developed in recent years, it has been successfully used for transmission electron microscopy (TEM) sample preparation, lithographic mask repair, and failure analysis of semiconductor devices. During FIB milling, material is removed by the physical sputtering action of ion bombardment. The sputter yield is high enough to remove a substantial amount of material, therefore FIB can perform a direct patterning with submicron accuracy. We succeeded in fabricating an x-ray phase zone plate using the Micrion 9500HT FIB station, which has a 50 kV Ga+ column. Circular Fresnel zones were milled in a 1.Opm-thick TaSiN film deposited on a silicon wafer. The outermost zone width of the zone plate is 170 nm at a radius of 60 pm. An achieved aspect ratio was 6:1.
Magnetotransport investigations and modelling of the Hg1-xCdxTe-anodic oxide accumulation system
Semiconductor Science and Technology, 1992
... Recent work by Mani [12] seems to have established quite convincingly that the experimental d... more ... Recent work by Mani [12] seems to have established quite convincingly that the experimental data are well described by a magnetic freeze-out picture. In this model the disorder-broadened donor impurity hand overlaps the conduction hand in the absence of a mag-netic field. ...
Te bicrystal containing a single grain boundary with an inversion layer has been investigated in ... more Te bicrystal containing a single grain boundary with an inversion layer has been investigated in the submillimetre wavelength range. For the first time t h e cyclotron resonance lines belonging to the various electric subbands of a quasi-two-dimensional carrier system at a grain boundary could be detected. The measured cyclotron masses and the subband densities determined from Shubnikov-de Haas experiments are compared with theoretical predictions and it is found that the data can be explained very well within the framework of a triangular well approximation model which allows for non-parabolic effects.
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