Extreme ultraviolet source

摘要

To both increase the efficiency of conversion into EUV radiation energy and also increase the amount of emerging EUV radiation in an EUV source a discharge tube is connected to a gas supply space for supply of the discharge gas which in located radially with respect to an optical axis. The discharge gas is supplied to the discharge space through the gas supply space, passes through the center opening of the anode, emerges from the discharge part and is afterwards evacuated from an evacuation opening. The anode and the cathode are connected to a pulse current source. Discharge plasma is produced and EUV radiation is formed by a heavy current pulse from the pulse current source within the discharge space of the discharge tube. The EUV radiation which has formed passes through a through-opening of the anode and is emitted to the outside.