Electrical behavior of zinc oxide layers grown by low temperature atomic layer deposition

We report on the electrical properties of thin film transistors based on zinc oxide (ZnO) layers grown by low temperature (100-170 degrees C) atomic layer deposition. As evidenced through Hall effect measurements, a drastic decrease of the carrier concentration occurred for ZnO films grown at 100 degrees C. Time of flight-secondary ions mass spectroscopy analysis revealed that this decrease is associated with an increase of the hydroxide groups in the ZnO layer which suppressed oxygen vacancy formation. Transistors fabricated from ZnO films grown at 100 degrees C exhibit a high I-on/I-off ratio (similar to 10(7)) and an encouraging intrinsic channel mobility (similar to 1 cm(2)/V s). (c) 2008 American Institute of Physics.