Electron beam lithography (EBL) is a key technology for the fabrication of new generation integral circuits and devices of electronics, photonics and nano-engineering. The computer simulation of the processes of electron exposure and development of the resist profiles in EBL is important for the optimization of this expensive technology process, due to the expensive equipment used in microelectronic fabrication, the use of sophisticated materials and the long chain of sequential steps required to obtain the desired microand nano-structure. In this work investigation of the exposure and the development of Poly-methyl methacrylate resist (PMMA) with 100 nm thickness on Si substrate is presented. Different simulation techniques are implemented for the estimation of the distribution of the absorbed energy in the sample during electron beam exposure and for the development of the resist profile. Results from Monte Carlo simulation softwares CASINO, TREM, SELID are presented.