Use of a helicon-wave excited plasma for aluminum-doped ZnO thin-film sputtering

Successful sputtering deposition of aluminum-doped zinc oxide (ZnO:Al) thin films was carried out using the helicon-wave excited plasma (HWP). The films deposited on soda-lime glass substrates exhibited a dominant [0001]-oriented growth with a small full-width at half maximum (0.32 deg) of the (0002) x-ray diffraction peak. The film deposited at 300 °C showed a resistivity of 5×10−4 Ω cm without any additional annealings. High optical transmittance greater than 80% was achieved in the visible spectral wavelengths. Similar to the success of the laser ablation technique, the HWP-sputtering method is expected to be developed as one of the versatile techniques for the preparation of semiconductor thin films.