A key advantage of the laser plasma source is its X-ray wavelength tunability, which is achieved by a convenient choice of the target atomic number. We provide a detailed analysis of the X-ray lithography parameters and demonstrate how to take full advantage of the flexibility of this source using both a simulation code called XLIMLAS and suitable experimental data. From these results, we determine the influence of each X-ray spectrum (related to a given target atomic number) on optimization of vital lithography characteristics such as wafer throughput, resolution and exposure conditions.