Christmas clean-room bakery

In the clean room facilities of Fraunhofer HHI, photonic chips are produced all year round on wafer scale that are used in communications, sensor technology and analytics. This also applies to the chips for quantum communications designed in cooperation with the UNIQORN partners. These consist of polymer waveguides that are only a few micrometers wide and can thus effectively guide light. In addition, thermo-optical functionalities such as switches and attenuators are realized with the help of metal electrodes. Finally, precise openings are etched into the chip surface, which serve as receptacles for the nonlinear optical crystals and filters. The sequence and details of these fabrication steps are defined in a protocol so that all functionalities are available and function correctly on the final wafer.

Now that Christmas is approaching, the clean-rooms at Fraunhofer HHI are set for a festive atmosphere. As in the bakeries, which are now running at full capacity everywhere, Christmas specialties are also produced here. A special production protocol from the secret recipe book was chosen for this purpose:

Take a silicon wafer and apply 1 teaspoon of polymer at 2000 rpm until a smooth layer has formed. Then everything is placed in the oven for 30 minutes before a pinch of gold is applied. After exposure under the lights of a Christmas tree, the excess material is removed.

And this is the result of our Christmas recipe: