Preferential growth of helium-doped Ti films deposited by magnetron sputtering

Abstract

The authors present a study on the influence of the bias voltages on the preferred orientation and microstructure of helium-doped Ti films. The films were deposited in a vacuum chamber by both direct-current magnetron sputtering and electron-cyclotron-resonance plasma-aided magnetron sputtering (ECR-PMS) methods. The preferred orientation and microstructure of the films were analyzed by x-ray diffraction (XRD) and transmission electron microscopy. They found that the preferred crystal orientation of helium-doped Ti films was controllably varied from (002) to (100) orientation by increasing the bias voltage (i.e., ion bombardment current and energy). The dominant bombardment effect on the orientation was from the Ar ions of the anode sheath in the magnetron sputtering plasma, and He bombardment also showed a slight influence on the orientation transformation at low trapped-helium content in the crystal. The XRD peak broadening of helium-doped Ti films prepared by ECR-PMS is much more serious than for conve...