Schottky-barrier Infrared Image Sensor 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.

EVALUATION OF A 512X512-ELEMENT PLATINUM SILICIDE SCHOTTKY-BARRIER INFRARED IMAGE SENSOR AND PILOT OBSERVATIONS OF CYGNUS X REGION

ABSTRACT We present evaluation of the performance of Mitsubishi's 512X512 element platinum silicide (PtSi) Schottky-Barrier infrared image sensor for application to astronomical observation. An infrared camera system, incorporating the PtSi array, was built and its performance was evaluated both in the laboratory and in observations. Dark current, DC stability, noise, quantum efficiency (QE), linearity, and uniformity were measured. Results of a series of measurements show that the array has potential capability for astronomical use. Several problems such as low QE and "splashes" are discussed. To demonstrate the effectiveness of the array by using this infrared camera, we have mapped an area of 8X9 square degrees of the Cygnus X region with a small telescope consisting of a silicon singlet lens. More than 1000 stars brighter than 6.5 mag in H-band were detected in the region.

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 model for charge transfer in buried-channel charge-coupled devices at low temperature

Charge transfer in buried-channel charge-coupled devices (CCDs) is explored with a one-dimensional numerical model which describes the capture and emission of electrons from a shallow donor level in silicon through the use of the Shockley-Read-Hall generation-recombination theory. Incorporated in the model are the three-dimensional Poole-Frenkel barrier lowering theory of A. K. Jonscher (1967) and J. L. Hartke (1968) and the low-temperature form of Poisson's equation. Reasonable agreement of the model with experimental data taken from the buried-channel CCDs of a PtSi Schottky barrier infrared image sensor is found. Moreover, the value for the capture cross section of electrons to the shallow phosphorus level in silicon inferred from the model follows the cascade theory for capture by M. Lax (1959) and agrees roughly with determinations made by other experimenters.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High-density Schottky-barrier infrared image sensor

The technologies for improving the photoyield of a Schottky-barrier detector and enlarging the effective photodetection area per pixel are discussed for realizing a high-density infrared image sensor with video quality. The design and performance of a 512 × 512 element platinum silicide Schottky-barrier infrared image sensor fabricated by these technologies are also described.