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VICTORIA ICHIZLI, MANUEL RODRÍGUEZ-GIRONÉS & HANS L. HARTNAGEL, Institut für Hochfrequenztechnik, TU Darmstadt, Germany

ABSTRACT

GaAs Schottky diodes are the most used devices for both frequency mixing and multiplying in THz range. Aiming for higher frequencies results in reducing the device dimensions. Anode dimensions in the THz range are often below one micron, which increases the importance of reliability issues in Schottky diodes. Ideality of the Schottky contact means low defect damage at the metal-semiconductor interface. Electrochemical metal deposition is a practically non-destructive method for Schottky contact formation. In order to avoid non-uniformity of potential distribution along the sub-micron anodes, pulsed bias is applied to the electrolyte-sample system. Pulsed deposition allows an application of high electric fields and thus more crystallisation centres are formed in comparison to DC deposition. This contribution describes the pulsed deposition method pointing out the parameters driving the quality of the final device. The processing techniques prior to deposition are discussed in respect to the improvement of the uniformity and quality