Enhanced electrical conductivity of zinc oxide thin films by ion implantation of gallium, aluminum, and boron atoms

Abstract

Effect of ion implantation on the conductivity of zinc oxide was examined by using highly resistive zinc oxide thin films deposited by rf magnetron sputtering at room temperature to reduce the effect of oxygen vacancies. With the doping by 1×1017 atoms/cm2 gallium the conductivity is 1.0×103/Ω cm for as-implanted film and it increases up to 3.7×103/Ω cm, the highest conductivity reported for zinc oxide films, with raising the annealing temperature in either a nitrogen or oxygen atmosphere. The conductivity of aluminum-doped films is slightly lower than those of gallium-doped films. Among the elements gallium, aluminum, and boron, gallium is the most effective in enhancing the conductivity and boron is the least. The order of the effectiveness is explained by the electronegativity of the dopants.

Photoluminescence of ZnO:Ga Thin Films Fabricated by Pulsed Laser Deposition Technique

“…On the other hand, Ga-doped zinc oxide (GZO) has been widely studied as a type of low resistivity n-type transparent conducting oxides (TCO) [6,7]. A number of studies have been devoted to improving the electrical conductivity and transmittance.…”

Effects of sputtering power on the properties of ZnO:Ga films deposited by r.f. magnetron-sputtering at low temperature

“…Compared with undoped ZnO, impurity-doped ZnO has low resistivity and good stability. ZnO 10.037 or Al) born, indium aluminum [1][2][3][4]. Most of the works related to ZnO use Al as dopant.…”

Zinc-Oxide Thin-Film Transistor With Self-Aligned Source/Drain Regions Doped With Implanted Boron for Enhanced Thermal Stability

“…It is presently suggested that B substituted for Zn [30] can be oxidized in an O 2 ambience. Such oxidized B is removed from ZnO as a donor.…”

“…Several techniques have already been employed to introduce B into ZnO, such as ion implantation [30], metal-organic chemical vapor deposition [31], [32], atomic layer deposition [33], photo-atomic layer deposition [34], PECVD [35], and radio-frequency (RF) magnetron sputtering [36]. Among these, implantation is a more versatile technique in terms of process simplicity, dosage control, and compatibility with a variety of device structures.…”