Electrostatic Modeling And ESD Damage Of Magnetoresistive Recording Heads

Abstract

Figure 1 shows cross sectional and air bearing surface (ABS) views of the experimental MR-type structure used in this study. The unshielded sensor is 2.0 pm by 25 pm by 300 A. The leads are spaced 3.0 pm from a conductive substrate. From an electrostatic point of view this device can be viewed as a system of conductors and dielectrics. Specifically, the MR-type device shown in Fig. 1 is modeled as a thin-film resistor that is capacitively coupled to the substrate. important to note is that the capacitor that is formed between the leads and the substrate has one edge exposed to air when the device is lapped. This metal/air/metal combination at the air interface forms a spark gap between the leads and the substrate. Figure 2 shows the electrical model incorporating the interesting combination of resistive, capacitive and spark gap properties of this device.