The light engine of the Chipscope project is a light-emitting diode (LED) array with separately addressable elements, nanoscale dimension, vertical 3D architecture, and well-controlled geometry. To manufacture such an array, advanced 3D nanodevice fabrication processing methods are required combining both bottom-up and top-down approaches, which include nanolithography, epitaxy, and etching steps.
In this case, the Institute of Semiconductor Technology (IHT) and the Laboratory for Emerging Nanometrology (LENA) at the Technische Universität Braunschweig, Braunschweig, Germany have successfully played their role in the project as a creator of nano LED arrays by designing and processing them based on 3D III-V compound semiconductor nanostructures.
The way to smallest LED structures starts with growing LED wafers at the facilities of the epitaxy competence center (ec²) using metalorganic vapor phase epitaxy (MOVPE). This method allows precise control of the growth parameters, which is very important, as the material quality strongly influences the efficiency of the LEDs. This epitaxy is subsequently followed by 3D processing steps including the transfer of the lithography mask pattern onto the LED wafers with sub-μm precision. Prior to integration with other components in a compact microscope optical system, the nano LED arrays are characterized using nano-optoelectrical measurement tools available at IHT and LENA to guarantee their functionality and performance.