Sub-100-nm current-perpendicular-to-plane sensor fabrication

Abstract

Two sets of processes for sub-100-nm current-perpendicular-to-plane (CPP) spin-valves (SVs) were developed. In the first method, a CPP SV was fabricated by using via-hole instead of small cell patterning. This method makes it easy to characterize the CPP spin valve films. The shunting effect has been analyzed in this method. In the second method, a resist layer for planarization, ionmilling, and wet etching for self-opening vla-hole in a self-aligned fashion by making use of the height difference between the cell and surrounding regions was introduced. This method is suitable for the actual recording heads with small dimension even without an ion-beam-deposition system. CPP sensors with size from 0.05 μm 0.05 μm to 0.4 μm · 0.5μm with different free-layer structures have been investigated by means of the first method.