A new design and fabrication process of an elastomer spatial light modulator (eSLM). The present invention resolves many known challenges and enables the eSLM to operate as programmable masks for the EUV lithography systems. Bottom electrodes are deposited and patterned on an insulation layer. A sacrificial layer is then deposited, patterned and polished on top of the bottom electrodes. A nitride shell forms a protection layer that prevents out-gassing and degradations of elastomer during operations. The sacrificial layer is removed, forming a cavity. An elastomer is injected at one end of the cavity and pulled into it by capillary forces. In an embodiment, the eSLM comprises a 2-D array of elastomer pillars, each containing a capacitive actuator with an elastomer as the supporting and dielectric structure. A stack of Mo/Si multilayer mirror is deposited on the surface to achieve a high reflectivity about 70% or more in EUV.