Optimization of photoluminescence from W centers in silicon-on-insulator

Abstract

W centers are trigonal defects generated by self-ion implantation in silicon that exhibit photoluminescence at 1.218 µm. We have shown previously that they can be used in waveguide-integrated all-silicon light-emitting diodes (LEDs). Here we optimize the implant energy, fluence and anneal conditions to maximize the photoluminescence intensity for W centers implanted in silicon-on-insulator, a substrate suitable for waveguide-integrated devices. After optimization, we observe near two orders of magnitude improvement in photoluminescence intensity relative to the conditions with the stopping range of the implanted ions at the center of the silicon device layer. The previously demonstrated waveguide-integrated LED used implant conditions with the stopping range at the center of this layer. We further show that such light sources can be manufactured at the 300-mm scale by demonstrating photoluminescence of similar intensity from 300 mm silicon-on-insulator wafers. The luminescence uniformity across the entire wafer is within the measurement error.

Microresonator-enhanced, Waveguide-coupled Emission from Silicon Defect Centers for Superconducting Optoelectronic Networks

“…The properties of silicon emissive defects in photonics-compatible SOI have not been studied or optimized until recently. Figure 1(d) shows an optimization of implant parameters performed in [4]. Unlike in bulk Si (blue triangles), W-center brightness in SOI is strongly dependent on implant energy.…”

“…Finally, the whole wafer is encapulated by a 1.5 µm PECVD oxide. More detail on fabrication can be found in [4]. Waveguides are designed to be 350 nm wide such that they are single-mode at 1220 nm.…”

Microring resonator-coupled photoluminescence from silicon W~centers

“…Implant and anneal conditions were chosen to yield the optimum W center brightness as determined in Ref. [14].…”

“…While it is off, the temperature begins to increase, reaching 40 K in approximately 12 minutes. W-center brightness drops by 12% between 28 K and 40 K and then drops off precipitously above 45 K [24,14]. All measurements in this work were taken between 28 K and 40 K.…”

“…In prior work on silicon defect centers, waveguides were not used because PL collection has always occurred directly above the structure being pumped, i.e., normal to the surface of the sample. Several of these devices were on silicon-on-insulator of dimensions that could potentially support waveguides [12,13,14]. Other studies have shown coupling of defect centers to suspended microdisk [15] and photonic crystal [16,17] cavities; however, resonator coupling of W centers has not been shown.…”