Recording on PZT and AgInSbTe thin films for probe-based data storage

In this paper, we propose microprobe-based electrical and thermal recording techniques for application to high-density data storage. A microheater integrated at the free end of a thermal microprobe is formed by diffusion of boron for 3 hrs at 1160/spl deg/C and is supported by two conductive silicon legs. When flowing a pulsed current through the legs, the heater is electrically heated in a short time. Primary experiments for electrical and thermal recording are evaluated using sol-gel processed PZT and AgInSbTe thin films as storage media. For electrical recording on the PZT film, a voltage pulse is applied between a conductive tip and the PZT film. The nano-sized ferroelectric domains are easily switched by the applied voltage. The smallest marks were below 100 nm in diameter, which correspond to bit densities over 70 Gb/in/sup 2/. For thermal recording on AgInSbTe, the conductive tip is Joule heated by flowing a current and then the heated tip undergoes a local phase change (amorphous to crystalline or crystalline to amorphous). To read the formed mark, we measure the electrical resistance between a bottom electrode of AgInSbTe and the conductive tip because the electrical resistance of the amorphous state is higher than that of the crystalline state.