Charge Sweep Device Research Articles

High-performance 801×512-element PtSi Schottky-barrier infrared image sensor

A high-performance 801×512-element PtSi Schottky-barrier infrared image sensor has been developed with an enhanced Charge Sweep Device (CSD) readout architecture. In the enhanced CSD, the power consumption of the CSD has been reduced by employing a multiphase CSD with an on-chip multiphase CMOS clock generator. Flexible vertical scan is also possible using a newly developed transfer gate scanner. A large fill factor of 61% is obtained in spite of the small pixel size of 17×20μm2. The differential temperature response and noise equivalent temperature difference with f/1.2 optics at 300K were 2.2×104 electrons/K and 0.037K, respectively. The saturation signal level was 2.1×106 electrons and the total power consumption of the device was less than 50mW.

Monolithic Schottky-barrier infrared image sensor with 71% fill factor

An improved 512 x 512-element PtSi Schottky-barrier IR image sensor (512 x 512 IRCSD) has been developed using the charge sweep device (CSD) readout architecture and 1.2-[mu]m minimum design rules. Finer pattern process technology enhances the advantage of the CSD readout architecture, enlarging the fill factor without sacrificing the saturation signal level. A large fill factor of 71% is achieved in spite of a small pixel size of 26 x 20 [mu]m[sup 2]. At the Schottky-barrier detector reset voltage of 4 V, the differential temperature response with f/1.2 optics at 300 K and saturation signal level were 3.2 [times] 10[sup 4] electrons/K and 2.9 [times] 10[sup 6] electrons, respectively. The noise equivalent temperature difference was estimated as 0.033 K with f/1.2 optics at 300 K. The improved 512 x 512 IRCSD was designed to be operated either in the field or frame integration interlace modes for versatility.

A camera using a 1040�1040 array

A JHKK′ survey camera based on a 1040×1040 PtSi “Charge Sweep Device” has been constructed in a joint programme of the University of Tokyo, the National Astronomical Observatory of Japan and the South African Astronomical Observatory. We describe its design, construction and initial testing.

1040 X 1040 infrared charge sweep device imager with PtSi Schottky-barrier detectors

We have developed a 1-Mpixel infrared charge sweep device (IRCSD) imager for thermal imaging in the 3- to 5-μm band. The device of this imager is a 1040 x 1040 monolithic PtSi Schottky-barrier (SB) array using the charge sweep device (CSD) readout architecture. The pixel size is 17 x 17 μm² and the fill factor of this device is 44%. In this imager system, four video signals are read out from four independent channels on the device. The processing of these four outputs, such as sample and hold (S/H), and offset control and image correction, is performed in parallel, after which these outputs are combined to produce high-definition TV (HDTV; 1125 lines, 30 Hz) format thermal image in real time. The noise-equivalent temperature difference (NETD) with <i>f</i>/1.2 optics at 27°C background is 0.13°C at the HDTV output stage.