GROWTH AND STRUCTURE OF TI FILMS DEPOSITED ON CHEMICALLY POLISHED MGO(100) SUBSTRATES

The growth and structure of Ti films deposited at various temperatures in vacuum of about 10(-6) Pa on chemically polished MgO(100) substrat es with heat treatment at 900 degrees C for 30 min and without heat tr eatment have been studied by means of transmission electron microscopy . It is found that the thin layer, whose thickness is up to about 5 nm , is composed of fee TiHx and TiOy crystallites at an early stage of d eposition. The growth of hcp Ti crystallites becomes dominant when the substrate temperature is raised to above 800 degrees C. The 50 nm thi ck Ti films heated at 800 degrees C for 30 min immediately after being deposited at room temperature are found to be far better defined epit axial films with only (10 . 1) orientation than those deposited at 800 degrees C. The 50 nm thick Ti films deposited at room temperature on as chemically polished MgO(100) substrates without heat treatment chan ge from amorphous to epitaxially grown ones with (10 . 1) orientation when heated at temperatures above 800 degrees C for 30 min in vacuum. This shows that the heating of Ti films deposited at room temperature on as chemically polished MgO (100) substrates without heat treatment is more effective for the epitaxial growth.