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A typical probe for scanning Kelvin probe microscopy (SKPM) consists of an atomic force microscopy (AFM) probe with a metallic coating. Such probes result in a large sensing area and lead to poor spatial resolution due to the stray-field effect. With electroless Ag plating (EAP), we employed an AFM system to form a Ag nanodot (AND) at the apex of the probe tip, which reduces the sensing area of the SKPM probe, thereby suppressing the stray-field effect. It was revealed that the tip with an AND structure had improved the spatial resolution in SKPM. Our experimental results showed that the EAP process can be completed in a few seconds, implying that localized EAP is a simple and rapid process for preparing an AND structure at the tip apex in SKPM measurements

A C 4 F 8 /He inductively coupled plasma-reactive ion etching (ICP-RIE) was studied to improve the etching conditions of quartz glass. The influences of C 4 F 8 flow rate, He flow rate, chamber pressure, inductively coupled plasma (ICP) power, bias power and cooling temperature were investigated. A report is presented on an optimum etching condition for fabricating quartz-based optical components considering their application in diffractive optical element (DOE) devices. As per these etching results, the etched microstructure exhibited a depth of 44.2 μm and a vertical sidewall angle of 89°resulting from an ICP power of 3000 W, a bias power of 200 W, a chamber pressure of 2.5 mTorr and an etching time of 120 min in a mixture of C 4 F 8 and He gases with 30 and 100 sccm flow rates, respectively. The successful fabrication of the DOE component by ICP-RIE is reported. This can be used to provide the uniform light intensity distribution for a DOE device.

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This paper presents a parallel zero voltage switching (ZVS) dc-dc converter with series connected transformers. In order to increase output power, two transformers connected in series are used in the proposed converter. Two buck-type converters connected in parallel have the same switching devices. The primary windings of series connected transformers can achieve the balanced secondary winding currents. The current doubler rectifiers with ripple current cancellation are connected in parallel at the output side to reduce the current stress of the secondary winding. Thus the current ripple on the output capacitor is reduced and the size of output choke and output capacitor are reduced. Only two switches are used in the proposed circuit instead of four switches in the conventional parallel ZVS converter to achieve zero voltage switching and output current sharing. Therefore, the proposed converter has less power switches. The ZVS turn-on is implemented during the commutation stage of two complementary switches such that the switching losses and thermal stresses on the semiconductors are reduced. Experimental results for a 528W (48V/11A) prototype are presented to prove the theoretical analysis and circuit performance.