Laser plasma x-ray contact microscopy of living specimens using a chemically amplified epoxy resist

Abstract

We report on the use of an epoxy based chemically amplified resist, to produce x-ray images of living biological specimens, exposed with laser plasma generated soft x rays, in the water window (2.3–4.4 nm). The photoresist response was at least two orders of magnitude “faster” than polymethyl methacrylate, the standard resist used so far in soft x-ray contact microscopy. Atomic force and scanning electron microscopy of the biological specimen images, recorded in the resist, clearly showed the flagella of the motile green alga, chlamydomonas, suggesting a lateral resolution better than 150 nm. The resist was also capable of providing height features, as small as 20 nm, in atomic force microscope depth profiles and discriminating the flagella intersection areas.