The microelectronic industry requires more and more low consumption and high reliability solutions. In this scenario the silicon nanocrystal memories (Si-nc) are one of the most mature technologies able to replace the Flash floating gate in NOR embedded applications. The main advantages of Si-nc memories are: the full compatibility with the CMOS process using a reduced number of masks (1) and the robustness against SILC (2). In this paper we present an experimental work on the optimized silicon nanocrystal cell industrially manufactured, where the reliability is improved (3). In particular the impact of silicon nanocrystals size and temperature on cell programming window is shown. Moreover we demonstrated for the first time at our knowledge that it is possible to achieve 1Mcycles endurance characteristic in the temperature range of [-40°C; 150°C], programming by channel hot electron (CHE) and erasing by Fowler-Nordheim (FN).