New universal technique for plan-view FIB preparation with no additional equipment or manual manipulations

We propose a new method for preparing lamella in a plan-view section, which can be implemented on any FIB-SEM equipment. We solved the problem of reorienting the sample-lamella by 90° by a sequence of two tilts by 45° and rotating the working stage with one intermediate operation of welding the sample to the half-grid in the microscope working chamber. The combination of these operations allows reorienting the sample surface by 90° in the vertical plane without using pre-tilted tables, rotating manipulators, removing the sample from the chamber or manual operations. Using a high electron mobility transistor sample as an example, we demonstrate the efficiency of the method, studied and analyzed the cores of threading edge dislocations in the AlGaN heterostructure in the [001] growth direction using high-resolution transmission electron microscopy. The proposed method simplifies the FIB procedure for preparing lamellas in a plan-view section, eliminating the need for additional devices, manual operations and the need to remove the sample into the air, which allows using the method for samples sensitive to oxidation in the atmosphere.