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Here we discuss the wafer-scale fabrication process flow of aluminium airbridges for microwave (MW) interconnects on lithium niobate on Damascene silicon nitride (LNOD) photonic chips. We also discuss the subsequent chip release procedure that preserves the bridges allowing for safe release of these delicate structures.

Here I explain the KOH simulator software (ACES) from University of Chicago [1] for a chain process of DRIE followed by KOH undercut. This software is very simple yet power to understand how Si etching works and design the mask to optimize the etch speed and crystal planes [2].

Resist removal is an essential step for multi-layer lithography processes where a clean and contamination-free surface is essential to avoid shadow etching patterns from resist leftovers. We show that a short \mathrm{O_2} plasma exposure followed by a full NMP solution cycle removes the resist fully and leaves the surface contamination free.

In this report I monitor a full successful cycle of critical point drying (CPD) run for drying MEMS sensors after wet release using KOH etching. The pressure and temperature of the CPD tool (Tousimis) is monitored during the process and plotted in a P-T diagram with \mathrm{CO_2} critical point. A few notes for higher yield in the drying process are mentioned in this report as well.

A few important points in data conversion and mask processing of multilayered Ebeam lithography is discussed. The conversion is done using Layout Beamer software at EPFL CMi cleanroom.