ZnO films have been grown by atomic layer deposition (ALD) using diethylzinc (DEZn) and H2O as reactant gases. The diborane (B2H6) gas has also been successfully used as an n-type dopant gas to obtain low-resistivity ZnO films. A high electron mobility of about 30 cm(2)/V s was obtained for undoped ZnO films of 220 nm thick, and a low resistivity of 6.4 x 10(-4) Omega cm was achieved for B-doped ZnO films of only 200 nm thick. It was found that the electrical properties of ZnO films strongly depend on the injected amount of B,H, during the deposition and on the injection timing of B2H6 relating to DEZn and H2O.