Method of producing coating using negative DC pulses with specified duty factor

A method for the production of a coating made of a ceramic, electrically non-conducting material, on a surface of a workpiece, comprising:

• placing the workpiece in, and insulating the workpiece from a vacuum chamber;
• a first process step wherein at least one of an oxide and nitride former, acting as at least one first material, is converted into a gaseous state and is at least partially ionized in the vacuum chamber using a first electrical voltage;
• a second process step wherein at least one of nitrogen and oxygen, acting as at least one second material, is introduced into and at least partially ionized in the vacuum chamber using the first electrical voltage;
• and
• at least during the second process step, applying a second voltage to the workpiece for depositing at least one of an electrically non-conducting oxide, nitride, and oxinitride layer on the surface of the workpiece, the second voltage being a negative pulsating dc voltage having a period and a pulse duty factor, the period being a few microseconds and the pulse duty factor being between 60 and 90% of the period.