Pt silicide/poly-Si Schottky diodes as temperature sensors for bolometers

TL;DR

This paper demonstrates the development of CMOS-compatible platinum silicide/poly-Si Schottky diodes as efficient, manufacturable temperature sensors for microbolometer radiation detectors, with significant temperature coefficients of voltage.

Contribution

It introduces a low-temperature process for fabricating platinum silicide/poly-Si Schottky diodes on artificial substrates, suitable for microbolometer applications.

Findings

Diodes exhibit a temperature coefficient of about -2%/°C from 25 to 50°C.

The layer structure and phase composition were characterized by electron microscopy and X-ray analysis.

The process is CMOS-compatible and suitable for manufacturing microbolometer temperature sensors.

Abstract

Platinum silicide Schottky diodes formed on films of polycrystalline Si doped by phosphorus are demonstrated to be efficient and manufacturable CMOS-compatible temperature sensors for microbolometer detectors of radiation. Thin-film platinum silicide/poly-Si diodes have been produced by a CMOS-compatible process on artificial Si$_3$N$_4$/SiO$_2$/Si(001) substrates simulating the bolometer cells. Layer structure and phase composition of the original Pt/poly-Si films and the Pt silicide/poly-Si films synthesized by a low-temperature process have been studied by means of the scanning transmission electron microscopy; they have also been explored by means of the two-wavelength X-ray structural phase analysis and the X-ray photoelectron spectroscopy. Temperature coefficient of voltage for the forward current of a single diode is shown to reach the value of about $-$2%/$^{\circ}$C in the temperature interval from 25 to 50$^{\circ}$C.