Method of processing a target material

A method of processing a target material, comprising:

• irradiating a multilayer structure with a radiation beam, the multilayer structure comprising at least a target layer comprising the target material and an additional layer not comprising the target material, wherein:
• the additional layer is metallic;
• the target layer is irradiated through the additional layer during the irradiation of the multilayer structure;
• the radiation beam passes partially through the additional layer to the target layer during the irradiation of the multilayer structure, such that the radiation beam transfers energy to the target layer and the additional layer by depositing energy both in the target layer and in the additional layer;
• and
• the transfer of energy from the radiation beam to the target layer and to the additional layer is such as to cause a thermally-induced change in the target layer, the thermally-induced change comprising crystal growth in the target material.