Electrical and optical characterization of planar MSM structures including /spl delta/-doped GaAs layers

In this work the influence of one and two (Si) /spl delta/-doped GaAs layers on the electrical and optical properties of MSM photodetectors has been studied. The sheet concentration and position of /spl delta/-doped layers in the structure were confirmed from C-V and Hall measurements. The properties of TiPtAu and TiPdAu Schottky contacts of MSM structures were analyzed and for interdigited MSM structures lateral measurements of dark and photocurrent current I-V characteristics were investigated. In the spectral characteristics of /spl delta/-doped layers, the presence of Franz-Keldysh oscillation are observable. The high speed measurements revealed that /spl delta/-doped layers effect the trapping of generated carriers and give rise to a decrease in the speed of /spl delta/-doped GaAs MSM photodetectors.