PROCESS FOR PRODUCING MAGNETORESISTANCE EFFECT ELEMENT AND PROGRAM FOR PRODUCING MAGNETORESISTANCE EFFECT ELEMENT

摘要

This invention provides a process for producing a magnetoresistance effect element having a high MR ratio. The production process comprises forming a first ferromagnetic layer constituting a first ferromagnetic body layer, forming a barrier layer constituting a tunnel barrier layer formed of a metal oxide on the first ferromagnetic body layer, and forming a second ferromagnetic layer constituting a second ferromagnetic body layer on the tunnel barrier layer. The formation of the barrier layer is characterized in that a metal film is formed and the metal film is then naturally oxidized under heating conditions. The natural oxidation is a treatment in which a treatment object is exposed to an oxygen gas or an oxygen gas-containing gas (for example, a mixture composed of an inert gas and an oxygen gas). In this natural oxidation, oxidation is carried out without subjecting the oxygen gas to plasmatization or the like.