The surface roughness of poly(methylmethacrylate) (PMMA) with various molecular weights, using 50 keV electron beam, has been investigated at reduced developer temperatures. As the developer temperature decreased, the magnitude of the surface roughness increased rapidly while the contrast curves merged into a single curve below 0 degrees C. A sharp drop in roughness at the bottom of the resist was observed for all temperatures investigated. At each temperature, the higher molecular weight PMMA had higher maximum roughness.