Charge storage in AlGaAs/GaAs heterojunction surface channel CCDs

摘要

A novel surface channel charge-coupled device (CCD) using an AlGaAs/GaAs heterostructure is presented. Charge storage device characteristics have been determined relative to the unintentionally doped and depleted AlGaAs layer. This layer serves as an effective substitute for the traditional silicon dioxide insulator in a MOS diode. At Q/sub sig/=0 and x1, where x is the aluminum mole fraction, the heterostructure has shown a near one-to-one correspondence between the effective gate voltage and the surface potential. It is shown that the material properties of the AlGaAs layer permit better control of the surface potential and charge transfer, thereby offering the possibility of performance superior to current Si-MOS CCDs.