  Topological Weyl semimetal WTe2 with large-scale film form has a promising
prospect for new-generation spintronic devices. However, it remains a hard task
to suppress the defect states in large-scale WTe2 films due to the chemical
nature. Here, we significantly improve the crystalline quality and remove the
Te vacancies in WTe2 films by post annealing. We observe the distinct
Shubnikov-de Haas quantum oscillations in WTe2 films. The nontrivial Berry
phase can be revealed by Landau fan diagram analysis. The Hall mobility of WTe2
films can reach 1245 cm2V-1s-1 and 1423 cm2V-1s-1 for holes and electrons with
the carrier density of 5 * 10^19 cm^-3 and 2 * 10^19 cm^-3, respectively. Our
work provides a feasible route to obtain high-quality Weyl semimetal films for
the future topological quantum device applications.
