Hydrogen Effects on the Electrical Conductivity of Pulsed Laser Deposited ZnO Thin Films

ABSTRACT

Well c-axis oriented 320 nm and 160 nm thick ZnO thin films were deposited with pulsed laser deposition on Pt/Ti/SiO₂/Si(100) substrates. Diode characteristics of Au/ZnO/Pt in electrical conductivity were observed. The conductivity in forward bias was sensitive to the hydrogen annealing but almost insensitive in reverse bias. The conductivity of 320 nm thick film in forward bias increased from 6.1 × 10⁻⁵ Ω⁻¹ cm⁻¹ in as-deposited film to 3.3 × 10⁻³ Ω⁻¹ cm⁻¹ in hydrogen annealed one at 200°C. The observed dielectric constant 70 was much higher than that of ceramic ZnO. Dielectric anomaly at about 1 kHz was observed and attributed to the space charge.

keyword:

• ZnO
• hydrogen
• PLD
• thin film
• conductivity

PACS::

• 72.80.Ey
• 73.40.Rw
• 77.55.+f

ACKNOWLEDGEMENT

This work was supported by a Korea Research Foundation Grant (KRF-2000-005-Y00070).