Tunneling effects are crucial not only for MOS transistors but also for non-volatile semiconductor memory devices. In contrast to volatile memory devices they retain the stored information without external power supply. NVM devices can be read and programmed like random-access memory (RAM) devices, have a low power consumption, are mechanically robust, and offer the possibility of large-scale integration. They constitute about 10% of the total semiconductor memory market . However, simulation of such devices is often carried out using simplified compact models [269,270,271,272,273,274]. For the case of stacked gate dielectrics or hot electron injection such models do not capture the device physics and can reproduce measured data only on a fit-formula level. In this section some examples of conventional EEPROM and alternative devices will be studied using the tunneling models described above.