Attack Microchip Microcontroller IC Chip starts from deprocessing the external package of MCU, this is a basic technique for MCU crack and Microprocessor Source Code reading;
Attack Microchip Microcontroller IC Chip starts from deprocessing the external package of MCU, this is a basic technique for MCU crack and Microprocessor Source Code reading
Three basic deprocessing methods are used: wet chemical etching, plasma etching, also known as dry etching, and mechanical polishing. In chemical etching each layer is removed by specific chemicals. Its downside is its isotropic nature, i.e. uniformity in all directions. That produces unwanted undercutting. As a result, narrow metal lines will have a tendency to lift off the surface.
Isotropic etching also leads to etching through holes such as vias, resulting in unwanted etching of underlaying metallization. Plasma etching uses radicals created from gas inside a special chamber. They react with the material on the sample surface to form volatile products which are pumped out of the chamber. As the ions are accelerated in an electric field they usually hit the surface of the sample perpendicularly.