Abstract-This paper describes the modeling, design and fabrication of quarter-micron double delta doped AlGaAs/InGaAs charge coupled devices whose epitaxial layers and geometry were based around the device structure of commercial pHEMTs. A quasi-two-dimensional physical model has been developed to investigate the properties of this novel 2 dimensional electron gas charge coupled device (2DEG-CCD). This physical model allows the characteristics of the InGaAs transport channel as well as the DC characteristics of the device to be predicted within a reasonable amount of time. This model also shows how 'individual' charge packets can be controllably transferred through the device when appropriate clocking voltages are applied to the gates of the CCD. This capacitive gate structure device is then shown to be successfully fabricated using established GaAs heterostructure fabrication techniques to ensure good repeatability. The DC characteristics of the fabricated charge coupled device delay line are included.Index Terms-2-DEG charge coupled devices, delay line, quasi-2d physical modeling, simulated charge transfer.

This paper presents the first reported quarter-micron double delta doped AlGaAs/ InGaAs charge coupled device for microwave frequency filter applications. The design and fabrication of conventional and multi tapped delay line MMICs for RF filter applications are also discussed. The device is implemented as a recessed capacitive gate structure which is fabricated using established GaAs heterostructure MMIC technology to ensure good repeatability. In transistor mode, the three stage device behaved as a multi-gated pseudomorphic high electron mobility transistor with a drain-source saturation current of 32 mA and an off-state drain-gate breakdown voltage of 2.8V