Monolithic optical link in silicon-on-insulator CMOS technology

Abstract

Abstract:This work presents a monolithic laterally-coupled wide-spectrum (350 nm < λ < 1270 nm) optical link in a silicon-on-insulator CMOS technology. The link consists of a silicon (Si) light-emitting diode (LED) as the optical source and a Si photodiode (PD) as the detector; both realized by vertical abrupt n + p junctions, separated by a shallow trench isolation composed of silicon dioxide. Medium trench isolation around the devices along with the buried oxide layer provides galvanic isolation. Optical coupling in both avalanche-mode and forward-mode operation of the LED are analyzed for various designs and bias conditions. From both DC and pulsed transient measurements, it is further shown that heating in the avalanche-mode LED leads to a slow thermal coupling to the PD with time constants in the ms range. An integrated heat sink in the same technology leads to a ∼ 6 times reduction in the change in PD junction temperature per unit electrical power dissipated in the avalanche-mode LED. The analysis paves way for wide-spectrum optical links integrated in smart power technologies.

Charge carrier transport and electroluminescence in atomic layer deposited poly-GaN/c-Si heterojunction diodes

“…The measured spectrum (Fig 8(b)) is centered around the 1.12 µm wavelength corresponding to the Si bandgap (E g−Si =1.12 eV) with a full-width-halfmaximum (FWHM) ∼ 96 meV at 300 K. The observed FWHM is in excess of ∼1.8kT 43 because of light being emitted from silicon, an indirect band gap semiconductor where interaction with phonons during the radiative recombination process leads to the broadening of the EL-spectrum compared to that in direct band-gap semiconductors 44,45 . Both the peak wavelength and the FWHM are in good agreement when compared with standard p-n junctions in silicon 46 .…”

“…This is so because I PD /I LED =η PD · η ext. · η LED , where η PD/ext./LED is the IQE of detection in the PD/extraction efficiency of light/IQE of the LED, respectively 46 . Out of the three efficiencies, only η LED is a function of I LED .…”

Reconfigurable Silicon Photonic Processor Based on SCOW Resonant Structures

“…Therefore, we prefer to use an external optical source. We also notice the recent development in on-chip silicon light-emitting diodes (LEDs) [35], [36]. The wide spectrum of silicon LEDs could be a proper light source for applications like bio-sensing.…”

Towards electrostatic doping approaches in ultra-thin body semiconductor materials and devices

“…The measured spectrum (Fig 6.9(b)) is centered around the 1.12 µm wavelength corresponding to the Si bandgap (E g−Si =1.12 eV) with a full-width-half-maximum (FWHM) ∼ 96 meV at 300 K. The observed FWHM is in excess of ∼1.8kT [157] because of light being emitted from silicon, an indirect band gap semiconductor where interaction with phonons during the radiative recombination process leads to the broadening of the EL-spectrum compared to that in direct band-gap semiconductors [247,248]. Both the peak wavelength and the FWHM are in good agreement when compared with standard p-n junctions in silicon [249].…”

“…This is so because I PD /I LED =η PD • η ext. • η LED , where η PD/ext./LED is the IQE of detection in the PD/extraction efficiency of light/IQE of the LED, respectively [249]. Out of the three efficiencies, only η LED is a function of I LED .…”