Manufacturing Methods of Spin Tunnel Magnetoresistive Elements with Synthetic Antiferromagnet

The article provides a review of modern technological methods of manufacturing spin-tunnel magnetoresistive (STMR) elements with a synthetic antiferromagnet (SAF), as well as technological processes that can increase the percentage of yield of suitable products, manufacturability and provide the required magnetic parameters of STMR elements. The relevance of research is provided by the potential and actual use of STMR nanostructures in the basis of nano- and microelectronics products such as linear and threshold magnetic field transducers, electric current transducers, magnetoresistive non-volatile memory cells, biosensors. In order to increase sensitivity to the magnetic field and optimize the electrical characteristics of magnetoelectronic products, STMR nanostructures with a synthetic antiferromagnet (SAF) is used, which is a combination of two ferromagnetic layers separated by a thin non-magnetic layer and connected through the exchange interaction of Ruderman-Kittel-Kasuya-Iosida. The STMR elements manufacturing process consist of magnetron sputtering for STMR nanostructures; creation of a topological pattern of STMR elements; deposition of the dielectric layer, forming a metallization layer, deposition of passivation layer. There are two the most common approaches for manufacturing of STMR elements. The first way involves ion beam etching of nanostructures through a photoresist mask obtained by direct photolithography; in the second way a metal mask and "lift-off" lithography are used. The research presented in the article makes it possible to determine and formulate common approaches and methods for the manufacturing of STMR nanostructures with SAF and elements based on them.