Proton-bombardment isolated GaAlAs/GaAs charge-coupled devices

Proton bombardment is used for the first time as a channel isolation technique to fabricate buried channel homojunction charge-coupled devices (CCDs) on n-GaAs channel on GaAs substrate and heterojunction CCDs of n-Ga(1-x)Al(x)As on GaAs. The CCD structure is a Schottky-barrier gate buried channel 3-phase device with 30 transfer gates. The channel-stop bombardment was carried out at room temperature with an energy of 200 keV and a total dose of 10 to the 15th/sq cm. The CCDs were tested with electrical charge injection and direct readout. The charge transfer efficiency was found to be greater than 0.999 per transfer for both GaAs and GaAlAs. The proton-bombardment isolated devices were compared with similar devices using mesa isolation and were found to perform similarly.