The relative argon concentrations of dc-sputtered tungstenfilms were determined as a function of argon pressure, target-to-substrate voltage, substrate bias, and target-to-substrate distance, for both the diode and triode configurations. The results for filmssputtered in the diode mode support Winters and Kay’s conclusions that the adsorption mechanism is due to entrapment of energetic neutral argon atoms. This model, however, does not. apply for all the argon content in filmssputtered in the triode mode. An additional mechanism resulting in a greater entrapment of argon is proposed, namely, the entrapment of low energy argon ions originating from the supporting glow discharge. Measurements of the argon content of the tungstenfilms were determined using the rf spark-source mass spectrograph.