A picosecond excimer laser-plasma source has been constructed, which generates an x-ray average power of 2.2 and 1.4 W at the wavelengths required for proximity x-ray lithography : 1.4 nm (steel target) and 1 nm (copper target), respectively. The plasma source could be scaled to the 50-75 W x-ray average power required for industrial lithographic production by scaling the total average power of the commercial excimer laser system up to 1 kW. The 1 nm x-ray source is used to micromachine a 2.5 THz microwave waveguide-cavity package with a 48 mu m deep, three-dimensional structure, using the LIGA technique. The 1 nm x-ray source is also used to print 180 nm long transistor gates in the fabrication process of field-effect transistors.