Processes for manufacture and assembly of implantable medical devices are described. A gate insulating film of a MOS transistor is formed using the steps of forming an oxide film 12 formed on a floating gate 14 of a split-gate type non-volatile memory cell and of forming a tunneling insulating film 16 formed on the floating gate 14 and the oxide film 12. Methods which prevent a skilled individual from using reverse engineering tools and techniques to attain that level of understanding andor prevent anyone from performing such modifications can offer significant advantages to content creators who wish to protect their products. Material loaded into the chute is initially positioned in front of the ram, i. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated. If the differential voltage exceeds the second clamping voltage level, the second subgroup of Darlington connected transistors turn on and restore the differential voltage to a level less than the second clamping voltage level.