Preparation of High Temperature Superconductor Thin Films on Si Based Substrates by Excimer Laser Ablation, Film-Substrate Interactions, and Plasma Processing Effects on Crystallinity

Abstract

Thin films were prepared by excimer laser ablation from Y-Ba-Cu-O and Tl-Ba-Ca-Cu-O targets. The films were prepared upon amorphous quartz and crystalline Si (111) substrates in partial pressures of oxygen. The substrate-film interaction, crystallization, composition, and microstructure of these films verst_s the deposition condition variables were studied including, substrate temperature, oxygen partial pressure, laser fluence and repetition rate. Additional deposition variables include the substrate/substrate holder and plasma generation loop DC and RE bias conditions and the target which can be DC biased. With the various biasing/plasma conditions we have studied to date, we have been unable to lower the substrate deposition temperature required for crystallization of Y-Ba-Cu-O films by more than 50 degrees C. Films of Y-Ba-Cu-O produced upon Si (111) are shown to be superconducting.