Thermal Characterization of the 144 nm GMR Layer Using Microfabricated Suspended Structures Available to Purchase

The performance and reliability of GMR heads are influenced by the level of temperature rise, which may occur in the device during the normal operation or during an electrostatic discharge (ESD) event. However, the reliable electro-thermal modeling of the GMR sensor to predict the temperature rise, demands an accurate knowledge of the thermal properties of its constituent materials such as Al₂O₃ passivation and GMR layers. The lateral thermal conductivity of the GMR layer, which has not been measured previously, can largely influence the maximum temperature rise in the GMR sensor. The present effort will be directed at thermal characterization of the CoFe/Cu multilayer structures made of extremely thin periodic layers, using steady-state and frequency domain heating and thermometry in suspended bridges. The measurements are performed on several suspended structures with the lengths and widths in the range of 250 to 500 μm and 16 to 20 μm, respectively.