Monolithic integration of a suspended light-emitting diode with a Y-branch structure

Abstract

We describe a double-sided process for the monolithic integration of a light-emitting diode (LED) and a Y-branch structure on a GaN-on-silicon platform. The suspended LED and highly confined waveguides are fabricated by silicon removal with back-side thinning of the suspended membrane. When the LED is turned on, part of the light emission is confined by a suspended rectangular waveguide, and the light propagates laterally. The guided light is then coupled into two branching rectangular waveguides and diffracted into the air at the output facets. The light output can be tuned by the LED, opening the potential for more sophisticated integrated photonic circuits.

Simultaneous light emission and detection of InGaN/GaN multiple quantum well diodes for in-plane visible light communication

“…The in-plane VLC system is implemented on a 2-inch GaN-on-silicon wafer [21,22], which is thinned to 200-µm thickness for further silicon removal by chemical mechanical polishing. The device layers consist of a ~220-nm-thick p-GaN layer, 250-nm-thick InGaN/GaN MQWs, a ~3.2-µm-thick n-GaN layer, a ~400-nm-thick undoped GaN layer, a ~900-nm-thick Al(Ga)N buffer layer, and a silicon substrate.…”

Monolithic photonic integrated circuit with a GaN-based bent waveguide

“…And like for on-chip photonic integration the usage of existing standard silicon processing lines can therefore play a central role in cutting production costs for monolithic multicomponent system. The absorption of downward-emitting light by the silicon substrate can be eliminated through the removal of the silicon [21][22][23]. Wang et al showed on-chip photonic integration of p-n junction InGaN/GaN MQW devices and suspended straight waveguides with diverse functionalities on a GaN-on-silicon platform [5,23].…”

“…The absorption of downward-emitting light by the silicon substrate can be eliminated through the removal of the silicon [21][22][23]. Wang et al showed on-chip photonic integration of p-n junction InGaN/GaN MQW devices and suspended straight waveguides with diverse functionalities on a GaN-on-silicon platform [5,23]. On-chip optical interconnect between the transmitter and the receiver is able to be obtained through suspended waveguides, which are produced by a combination of silicon removal and backside III-nitride etching techniques.…”

A 30 Mbps in-plane full-duplex light communication using a monolithic GaN photonic circuit

“…Figure 3 demonstratesthe light propagation image of the on-chip photonic circuit when the top-left InGaN/GaN MQW-LED operates at a forward voltage of 3.5 V. In addition to the escape cones perpendicular to the wafer surface, suspended InGaN/GaN MQW-LED has many escape cones parallel to the wafer surface, which can couple the emitted light from the InGaN/GaN MQW-LED to form the in-plane light propagation [14,15]. Hence, the in-plane escape cones could be adopted as waveguides to manipulate the light propagation [16].…”