HIGH REP RATE HIGH-PERFORMANCE PLASMA-FOCUS AS A POWERFUL RADIATION SOURCE

Basic operational characteristics of the plasma focus are considered f rom design perspectives to develop powerful radiation sources. Using t hese ideas we have developed two compact plasma focus (CPF) devices op erating in neon with high performance and high repetition rate capacit y for use as an intense soft X-ray (SXR) source for microelectronics l ithography, The NX1 is a four-module system with a peak current of 320 kA when the capacitor bank (7.8 mu F x 4) is charged to 14 kV, It pro duces 100 J of SXR per shot (4% wall plug efficiency) giving at 3 Hz, 300 W of average SXR power into 4 pi. The NX2 is also a four-module sy stem. Each module uses a rail gap switching 12 capacitors each with a capacity of 0.6 mu F. The NX2 operates with peak currents of 400 kA at 11.5 kV into water-cooled electrodes at repetition rates up to 16 Hz to produce 300 W SXR in burst durations of several minutes. SXR lithog raphs are taken from both machines to demonstrate that sufficient SXR flux is generated for an exposure with only 300 shots. In addition, ha sh electron lithographs are also obtained requiring only ten shots per exposure. Such high performance compact machines may be improved to y ield over 1 kW of SXR, enabling sufficient exposure throughput to be o f interest to the wafer industry. In deuterium the neutron yield-could be over 10(10) neutrons per second over prolonged bursts of minutes.