<title>Electro-optical characterization of epitaxial and polycrystalline CoSi2 Schottky diodes</title>

Abstract

The infrared response of polycrystalline and epitaxial CoSi2/Si Schottky diodes with similar silicide thickness has been measured. For the polycrystalline diodes the quantum efficiency is found to be two times higher than for the epitaxial diodes, although both types of diodes present very similar barrier height. The observed improvement is attributed to grain boundary scattering of the excited carriers.

Nanosecond Response Found in Photoexcited Surface Carriers Generated by CoSix Nanoparticles on Si Substrate

“…An improved photoresponse as a result of adopting polycrystalline CoSi 2 /Si Schottky diodes has been proposed as a solution for Si-based infrared (1-10 mm) detectors for a decade. Roca et al 1) explained that the enhancements are due to the realization of high quantum efficiency by carrier scattering inside the CoSi 2 grains of a size of about 50 nm. CoSi 2 and CoSi x have been utilized as photoelectric conversion materials, 1) and their use has enabled the development of visible to infrared (up to 10 mm) sensors; 2) however, further exploratory research and development of CoSi x , including THz applications, has not been conducted to date.…”

“…Roca et al 1) explained that the enhancements are due to the realization of high quantum efficiency by carrier scattering inside the CoSi 2 grains of a size of about 50 nm. CoSi 2 and CoSi x have been utilized as photoelectric conversion materials, 1) and their use has enabled the development of visible to infrared (up to 10 mm) sensors; 2) however, further exploratory research and development of CoSi x , including THz applications, has not been conducted to date. On the other hand, variations in the CoSi 2 /Si Schottky barrier height have been realized by annealing effects at the interface.…”

“…This barrier height is in the range of those for CoSi x /Si systems which depend on annealing temperatures 3) and on the size of the CoSi x particles. 1) Current density and sensitivity were evaluated to be about 0.1 A/cm 2 and 420 mA/W when biased at 0 V, respectively. The sensitivity is closed to that of commercially used p-i-n photodiodes.…”