Optimization of fabrication processes of the mesa-type GaAs:Te blocked-impurity-band detector
In this work, the device structure of the mesa-type GaAs:Te blocked-impurity-band detector was designed. The fabrication processes were presented briefly, and optimization of the fabrication processes was investigated. A 3-micron-thick SiO2 film was deposited as resist to substitute for photoresist in the 50-micron-deep mesa etching process. In addition, a bi-layer photoresist lithography technique was adopted to optimize the process of electrode fabrication. It is demonstrated that the device quality can be improved significantly after optimization.
Design consideration of GaAs-based blocked-impurity-band detector with the absorbing layer formed by ion implantation
Drawbacks and problems of the traditional liquid-phase-epitaxy grown mesa GaAs-based blocked-impurity-band (BIB) detector are discussed. In order to improve device performance, a novel planar GaAs-based BIB detector with the absorbing layer formed by ion implantation is proposed and modeled. Physical models and key parameters used for simulation are presented. Our results reveal that the transition region between the absorbing layer and the blocking layer can be as narrow as 3.125 $$\mu \hbox {m}$$μm by adopting the novel design. Bias-dependent electric field characteristics are then obtained by taking into account the immaturity of GaAs-based material. Temperature-dependent dark current characteristics are also simulated to investigate the impurity-band effect. Finally, the dependences of dark current and photoresponse on the thickness of the blocking layer are studied. It is demonstrated that the effective dark current suppression and sufficient photoresponse level can be realized by a proper control over the thickness of the blocking layer.
Calculation of Complex Radiant Heat Load From Surrounding Radiator Surface Temperatures
Abstract A method for calculating the radiant heat exchange between an absorber and individual radiating components in its surroundings is reported. Radiator surface temperatures, ambient and absorber temperatures, and configuration factors for radiating components in the surroundings are used in the customary radiant heat exchange formulae. Simplified methods for calculating or estimating configuration factors for radiators of various shapes solely from angles, subtended at the absorber by the radiators are presented. The method has been verified in the laboratory under controlled conditions and has been used to advantage in the field studies. The method has advantages over the globe therometer method in certain applications.