A resistive-gate Al/sub 0.3/Ga/sub 0.7/As/GaAs 2DEG CCD with high charge-transfer efficiency at 1 GHz

Abstract

The fabrication and performance of an Al/sub 0.3/Ga/sub 0.7/As/GaAs modulation-doped resistive-gate charge-coupled device (CCD) are reported. The two-dimensional electron gas (2DEG) CCD, implemented as a 32-stage four-phase delay line, was tested at both low (1-13-MHz) and high (0.6-1.0-GHz) frequency. It exhibits a room-temperature charge-transfer efficiency (CTE) of better than 0.999 at clock frequencies from 10 MHz up to 1 GHz without a fat-zero signal and is limited by dark current below 10 MHz. The high-frequency test showed no CTE degradation up to 1-GHz operation. The CTE degraded at frequencies lower than approximately 5 MHz due to dark current. The charge-handling capability and minimum clock swing of the resistive-gate 2DEG CCD are calculated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>