Recently etched heavy ion tracks in MOS devices were filled with (semi)conducting materials to enable charge extraction from, or injection into the conducting channel below the Si/oxide interface, respectively. This leads to a family of novel electronic devices that we denoted as “TEMPOS” structures - that acronym stands for “Tunable Electronic Material with Pores in Oxide on Silicon”. In comparison with MOS-FETs, TEMPOS structures have some unique properties due to their additional parameters such as the track diameter, density, and shape, and the material embedded therein and its spatial distribution. This makes these novel structures much more complex, and it eventually leads to higher compactation of the TEMPOS circuits and to unexpected electronic properties. Depending on the choice of these parameters and the working point of these structures, TEMPOS elements can overtake the function of gatable resistors, condensors, photocells, hygrocells, diodes, sensors, and others. This work concentrates on some basic aspects of TEMPOS and gives some corresponding current /voltage relations and equivalent circuits.