A method of depositing material onto a substrate at cryogenic temperatures using beam-induced deposition. A precursor gas is chosen from a group of compounds having a melting point that is lower than the cryogenic temperature of the substrate. Preferably the precursor gas is chosen from a group of compounds having a sticking coefficient that is between 0.5 and 0.8 at the desired cryogenic temperature. This will result in the precursor gas reaching equilibrium between precursor molecules adsorbed onto the substrate surface and precursor gas molecules desorbing from the substrate surface at the desired cryogenic temperature. Suitable precursor gases can comprise alkanes, alkenes, or alkynes. At a cryogenic temperature of between −50° C. and −85° C., hexane can be used as a precursor gas to deposit material; at a cryogenic temperature of between −50° C. and −180° C., propane can be used as a precursor gas.