HfO[sub 2] Films Grown by ALD Using Cyclopentadienyl-Type Precursors and H[sub 2]O or O[sub 3] as Oxygen Source

thin films have been deposited onto p-Si(100) substrates by atomic layer deposition (ALD) using or and water or ozone as precursors. The purity of films was better when ozone instead of water was used as oxygen precursor. The use of together with ozone in the ALD window range, viz. 350–400°C, yielded films with less than 0.1 atom % C and H impurities. -processed film contained C and Cl, but again the use of ozone considerably reduced the impurity levels. When using as the metal source, the higher reactivity of ozone as compared to yielded slightly higher growth rate, smoother morphology, higher degree of crystallinity for thicker films, and a close to ideal density. Furthermore, with ozone no inhibition of the growth during initial ALD cycles could be detected. The growth of film on H-terminated Si with the process was retarded and the initial island-like growth took place resulting in rougher surface. With the process, the films showed the best leakage current density characteristics. Slightly higher capacitance equivalent oxide thickness values were calculated for the ozone-processed films.