A full-wafer process is presented for fast and simple fabrication of glass microfluidic chips with integrated electroplated electrodes. The process employs the permanent dry film resist (DFR) Ordyl SY300 to create microfluidic channels, followed by electroplating of silver and subsequent chlorination. The dry film resist is bonded directly to a second substrate, without intermediate gluing layers, only by applying pressure and moderate heating. The process of microfluidic channel fabrication, electroplating and wafer bonding can be completed within 1 day, thus making it one of the fastest and simplest full-wafer fabrication processes.

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The development of AlGaN pin photodetectors sensitive in the UV range with different narrow band active regions is reported in this paper. Structures were grown by metalorganic vapor phase epitaxy on (0001) sapphire substrates using three-dimensional GaN as well as high temperature AlN nucleation. Very high specific detectivities of 1×1014 cm Hz0.5 W-1 can be achieved based on optimized growth conditions of undoped and doped AlGaN layers with an Al-content ranging from 0% up to 100%. The crack-free AlGaN layers have edge dislocation densities in the range of 5×109 cm-2. Based on the two different nucleation types, pin layer structures were grown and fabricated to UV-A (320 to 365 nm) and UV-C (< 280 nm) photodetectors. The electro-optical performance of these photodetectors measured on-wafer will be presented in this paper, supplemented by the data of a single photodetector chip mounted in a TO 18 package.

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Improved Aluminum-Gallium-Nitride p-i-n photodetectors with different active regions are reported, designed for the measurement of UV-A (315 to 380 nm), UV-B (280 to 315 nm), and UV-C (< 280 nm) radiation. The spectral responsivity of Al x Ga 1-x N photodetectors can be tailored by bandgap engineering of the Al x Ga 1-x N layers and integration of filter layers. Intrinsically visible-blind p-i-n photodetectors are measured on-wafer and packaged in TO-18 headers. Photocurrent measurements in photovoltaic mode result in responsivity values of up to 0.21 A/W for UV-A (EQE = 70 %), 0.14 A/W for UV-B (EQE = 56 %), and 0.11 A/W for UV-C (EQE = 57 %), respectively. Room temperature dark current density values as low as 30 pA/cm² at a reverse bias of -3 V yield a specific detectivity of more than 4×10 14 cmHz 0.5 /W. Response time data of the p-i-n photodiodes indicate a rise time of 1.7 ns and a fall time (1/e) of 4.5 ns. Long term stability tests over 1000 h at an irradiance of 5 W/cm² demonstrate the potential of these photodetectors for demanding applications such as the continuous monitoring of high irradiance ultraviolet light sources. Index Terms-Aluminum gallium nitride, p-i-n diodes, Semiconductor epitaxial layers, Ultraviolet photodetectors. 1077-260X (c)