A high deposition rate of 0.69 mu m/min was achieved in the formation of diamond-like carbon (DLC) film with sufficient hardness and flatness under a high density, widely spread sheet-like plasma at room temperature. The argon plasma was generated by a de are plasma gun under a magnetic field and it decomposed the toluene gas which was fed into the deposition chamber. During the deposition, the substrate was negatively biased by radio frequency (rf) in order to improve the hardness of the films. The DLC films were characterized by Raman and infrared absorption spectrometers. An optical emission spectrometer and a quadrupole mass spectrometer were used to identify the radicals in the plasma. The influence of the discharge current on the film properties is discussed.