A numerical study of resolution and contrast in soft X-ray contact microscopy.

We consider the case of soft X-ray contact microscopy using a laser-produced plasma. We model the effects of sample and resist absorption and diffraction as well as the process of isotropic development of the photoresist. Our results indicate that the micrograph resolution depends heavily on the exposure and the sample-to-resist distance. In addition, the contrast of small features depends crucially on the development procedure to the point where information on such features may be destroyed by excessive development. These issues must be kept in mind when interpreting contact microradiographs of high resolution, low contrast objects such as biological structures.