The research of the properties of multilayer metallization of the structures “silicon on molybdenum” obtained by magnetron sputtering

Background. The interelement connection of modern power semiconductor devices must possess minimal electrical and thermal resistance, inductance and high mechanical strength in a wide range of operating temperatures. Metal layers coating the components of power semiconductor devices, silicon structures and molybdenum temperature compensators play an important role in the technology of such compounds. They must have high strength and adhesion to the surfaces of silicon structures, of molybdenum temperature compensators and solders, which are used in interelement connection technologies. The aim of this paper is to study the properties of surface multilayer metallization of interelement connections and molybdenum temperature compensators used in the structure “silicon-on-molybdenum” with low-temperature compounds of new generation high-performance power semiconductor devices. Materials and methods. Several options (Al-Ti-Ni-Ag, Ti-Ni-Ag, Ni-Ag and Ag) of multilayer metallization deposited by magnetron sputtering onto the ground surfaces of interelement connections and molybdenum thermal compensators are studied. To measure the adhesion strength of the multilayer metallization the method of measuring the scratch (scratch test) is used. The elemental composition of the metallization layers was determined by scanning with the electron microscope Quanta 200i 3D FEI using the mapping function possibilities. Results. It is established that the values of the basic element mass fraction in the multilayer metallization layers in silicon structures range from 97 to 99 % and in the multilayer metallization layers of molybdenum temperature compensators it varies from 97 to 98 %. The dependence of the adhesive strength of the coatings on the type of multilayer metallization of silicon structures and molybdenum temperature compensators, the total layer thickness and the type of heat treatment were studied. It was established that a four-layer metallization of Al-Ti-Ni-Ag after annealing in vacuum has the maximum adhesive strength on the surface of the silicon structures. A two-layer metallization Ni-Ag after annealing in vacuum possesses the maximum adhesive strength on the surface of the molybdenum temperature compensators. Conclusions. Four-layer Al-Ti-Ni-Ag systems obtained by magnetron sputtering after annealing in vacuum and two-layer Ni-Ag systems annealed in vacuum can be used as a coating for silicon structures and molybdenum temperature compensators respectively while manufacturing new generation power semiconductor devices.