Micromaching Techniques Of GMR Sensor

The development of modern science and technology and raising the level of human life is inseparable from the production of various sensor technology research and application. Almost every physical phenomenon adds a new membership to the variety of sensors. Magnetoresistance sensor is an important one of them. The physical principle of this kind sensor is the material under the effect of the magnetic field will change its electrical resistance. According to their different magnetic resistance we can define them as Hall, AMR, GMR, TMR and the CMR effect. Hall Effect and AMR effect had been developed and utilized for long time, they get widely used. Due to their scope process technique and limits apply condition, the application of TMR effect and the CMR effect is still in exploratory stage.On the first chapter, we give a briefly review to variety Magnetoresistance, and then focuses on the physical mechanism of GMR effects, based on "Spin-dependent scattering phenomenological model" and the "Two- current model". Different kinds of GMR structure are been introduced, including Multi-layer metal and Granular film.The necessary means to use spin valve GMR effect material is Micromaching Techniques. On the second chapter, we will show micro-processing technology involved in the process.On the third chapter, we focus on the most important micromachining part: graphics lithography. At the same time, we explored the parameters conditions for lithography etching. Illustrate the effect of parameters on lithography processing.ChapterⅣintroduces the mechanism of plasma etching, indicating that the main IBE process. Combination of ion source parameters used in experiments and spin valve metal film structure, summed up the appropriate etching parameters.ChapterⅤshows the test results of GMR sensors chip. Some apply examples of the GMR sensor chip which is ongoing on our experimental group are given, and further prospects of application and research is given too.