Amorphous Li3PS4 films were synthesized by pulsed laser deposition (PLD) at room temperature using Li3PS4 targets with excess lithium and sulfur. Raman and X-ray photoemission spectroscopies indicated that the Li3PS4 film synthesized with a stoichiometric amount of Li3PS4 target contained lithium-deficient phases such as Li4P2S6, Li2-xS and sulfur due to composition deviation caused during the ablation process. The film synthesized with a 14% Li2S-excess target (Li3.42PS4.21) contained fewer impurities, and exhibited a higher ionic conductivity of 5.3x10(-4)S/cm at 298K than the lithium-deficient film (3.1x10(-4)S/cm). The target composition is an important factor for the fabrication of highly conductive Li3PS4 films for electrolytes in thin-film batteries.