  We report on fully epitaxial FeSe0.5Te0.5 (FST) thin films with high-quality
grown on CaF2 (00l) substrate at a low temperature of 300{\deg}C by pulsed
laser deposition. The transport Jc of thin films is up to 1.36 MA/cm2 in
self-field and 0.97 MA/cm2 in 9 T at 4.2 K, indicating very weak field
dependence. A nearly isotropy of Jc ({\gamma}= Jc(H//ab)/Jc(H//c) as low as
1.09 at 9 T is achieved in the FST thin films. Moreover, no clear amorphous
interfacial layer presents between the film and the substrate probably
ascribing to low temperature and low laser repetition rate grown, while the
thickness of reaction layer is approximate 5 nm in many other works. The
evidences of transmission electron microscopy show some lattices with lateral
size of < 5 nm x 20 nm seem to be disturbed. Those location defects are thought
to be responsible for nearly isotropic behavior of superconductivity.
