Institute of Solid State Physics
|
|
SS22 WS22 SS23 WS23 SS24 WS24 Guidelines for Master Students
Microfabrication building blocks towards high frequency resonators for 5G RF filters applications Increasing usage of mobile wireless traffic, and thus an increasing amount of Radio Frequency (RF) filters has led to a growing demand of surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices. Recently, hybrid quasi-SAW/BAW resonators were reported, that show high potential in wideband and high frequency applications. These resonators present strong microfabrication challenges, requiring low resolution top electrode and Aluminum Scandium Nitride (AlScN) thin film pattering, a vertical etching profile of AlScN and smooth etched AlScN surfaces. Especially the etching poses a big problem, as irregular etching leads to huge losses in device performance. Different microfabrication technologies are available to etch AlScN, which can be divided into dry and wet etching techniques. Etching processes for two different etching methods are investigated, one wet using KOH and H3PO4, and the other dry, namely Ion Beam Etching (IBE), with the focus of both developments being smooth AlScN surfaces and steep sidewall angles. |
