Abstract
We tried to fabricate a CPP (Current Perpendicular to Plane) type spin transistor which is expected to have higher MR ratio instead of current-use CIP-GMR structure. For constructing a spin transistor structure, we introduced photolithography process. In order to make a Shottky barrier with higher barrier height between GMR base and n-Si collector, we used HF treatment of Si and inserted an Au underlayer as a metal with high workfunction. It was also possible to get ohmic contact by replacing the electrode metal from Cu to Al. Variation of collector current in magnetic field of simple spin transistor without insulator layer were observed. I-V characteristics of the junction clarified that oxidized Al thin film prepared in pure oxygen atmosphere at a pressure of 20 Torr for 5 hours thickness of insulator layer and Shottky barrier height were 3.8Å and 4.1eV, respectively.
