Surface preparation and wet cleaning for Germanium surface

The CMOS devices with Ge, considered as one of new materials for the later 5-nm generations, has been investigated since Ge should be mandatory material to enhance the electron mobility as replacement for Si. In this paper, we will propose new two techniques for surface preparation and wet cleaning, one of two techniques is in terms of PRE (Particle Removal Efficiency) on Ge surface, and the other is Ge corrosion caused by the dissolved oxygen effect. High PRE without Ge loss was achieved for surface preparation by using O 3 /NH 4 OH mixture. And to add to it, excellent selective Ni removal along germanidation (NiGe generation) without Ge corrosion was realized by reducing dissolved oxygen in chemistry.