Chemical Mechanical Planarization

Chemical Mechanical Planarization (CMP), also often referred to as Chemical Mechanical Polishing, is a process for planarizing and smoothing surfaces, which usually consist of two or more different materials. Separating, ablating and material property-changing processes are combined in the process, using nanoparticles as abrasive grains. This combination of chemical and mechanical material processing enables the uniform removal and planarization of thin-film wafer surfaces made of material combinations.

Planarization is achieved both locally, from structure to structure, and globally, over the entire wafer. Local planarization refers to the adjustment of height differences of adjacent structures, global planarization refers to the adjustment of height differences over the entire substrate surface. CMP is the only surface processing technology that can achieve global planarization. CMP is a standard process in the semiconductor industry for planarizing thin films. Materials such as dielectrics, polysilicon and metals can be processed. Polishing produces surfaces of high quality. CMP enables the production of multilayer systems and plays a key role in the development of powerful and highly integrated circuit components.

CMP is also used in optics, surface refinement and the manufacture of multilayer microsystems. At IMPT, CMP processes are mainly used as an intermediate step in the construction of multilayer electromagnetic actuators and sensors. A material composite made of Cu or soft magnetic material (NiFe, CoFe) embedded in polymer (photoresist or epoxy resin) is polished. Furthermore, CMP is used for planarization and refinement of various wafer surfaces (Si, polisilicon, glass, ceramics, etc.) Research is needed to adapt the process to increasingly complex material combinations.