A Study on the Preparation Conditions of Single Oriented (002) Hf Film on n-(001) Si

Abstract

We have investigated the preparation conditions of a single oriented (002) Hf film on n-(001) Si, by varying the sputtering parameters during deposition. The crystallinity and orientational plane of the prepared Hf films were evaluated by X-ray diffraction and cross-sectional transmission electron microscopy. We found that the single oriented (002) Hf film grows on the (001) Si substrate under the sputtering conditions of sputtering power above 50 W, substrate temperature of about 400°C, sputtering gas pressure below 2 mTorr and film thickness below 1000 Å, although a thin amorphous silicide layer is interposed between Si and Hf. Furthermore, it is also revealed that a (111) Al film, with excellent electromigration resistance, grows in a single oriented state on the (002) Hf film, because of the small lattice mismatch (0.8%) between (002) Hf and (111) Al two-dimensional superlattice cells.