Etching behaviors of tunneling magnetoresistive (TMR) materials by ion beam etching system

Abstract In data storage manufacturing, ion etching process is commonly chosen for the preparation of surface patterns, for example, under the read-write head of the hard disk drive (HDD) to form an air bearing surface (ABS). This read-write head consists of a multilayer thin film of different materials to form a tunneling magnetoresistive (TMR) device. In this work, we applied the Monte Carlo-based simulation package to calculate the etching yield of major materials in the HDD head’s structure. The plasma characteristic in the industrial-size ion beam etching (IBE) system has been studied by the special plasma diagnostic probes. Effects of input parameters in IBE system such as incident beam angle, ion beam current and gas flow in the system were considered. Plasma characteristic can be obtained from plasma I-V curve characterization. The sputtering yields of materials were found maximum when an incident angle is about 70° to the normal surface. The floating potential of plasma in the system with the ion/electron compensation from PBN is calculated.