Reverse saturation current is a term used in semiconductor diodes to describe the part of the reverse current caused by the diffusion of minority carriers from the neutral regions to the depletion region. In a PN junction diode, the reverse saturation current is due to the diffusive flow of minority electrons from the p-side to the n-side and the minority holes from the n-side to the p-side. This current is almost independent of the reverse voltage applied across the diode, but it increases with the rise of temperature of the junction diode. The reverse saturation current is also known as the leakage current or scale current. It is important to note that the saturation current is not a constant for a given device; it varies with temperature, and this variance is the dominant term in the temperature coefficient for a diode. A common rule of thumb is that it doubles for every 10 °C rise in temperature.