Design of a clean, high-brightness light source is presented for extreme ultraviolet/soft x-ray (EUV/SXR) lithography research and mask inspection. Basic characteristics of classical laser-Compton scattering are reviewed, and the laser and electron beam parameters at relatively low energy (EUV to SXR) photon generation are optimized. Recent achievements in each component technology are evaluated on a continuous wave (CW)-operated electron linac and energy recovery linac system, based on superconducting technologies at a 1.3 GHz operation frequency, 10 kW average power, short pulse laser, and optical super cavity with a 600- enhancement- factor at 10.6 μm wavelength. Combining both the CW electron beam and short pulse laser with super-cavity enhancement, flux and brightness laser-Compton source is designed at 6.7-nm wavelength. The technological gap in the present component technologies are discussed, as well as any further required developments.