Ideal mode operation of an InSb charge injection device

Unlike Si or HgCdTe CID (charge injection device) arrays, which normally operate at ∼1 MHz with the presence of a ≲ 10 percent fat zero (i.e., ideal mode), current InSb CID arrays fabricated on InSb substrates can operate either at a much lower clock frequency of ∼ 10 kHz (i.e., slow charge transfer mode), or when both row and column potential wells are partially filled with a large bias charge (i.e., charge sharing mode). The slow charge transfer mode is very ineffective in reading out signal charge from a large-area array and the charge sharing mode exhibits difficulties such as reduced readout efficiency, increased line capacitance, and a large photocurrent effect. By contrast, the ideal mode is free of these problems. In this paper we describe the design and fabrication of an InSb CID array, which for the first time, successfully demonstrates the ideal mode operation.