Origin of Heating Inside 3D FINFET and GAA Structures

The self-heating in 3D transistors below 32 nm is one of the most important factors that hinder its performance at higher biasing levels. In the present study, TCAD has been used to see the effect of self-heating on FINFETs and gate-all-around (GAA) structures at different node sizes. In FinFET with a decrease in node size, the temperature of the node also decreases due to reducing in self-heating. Maximum heating is seen in the 30 nm node where the temperature of the fin rises to 427 degrees C and due to that, a small bending of the I-V curve has also been observed at higher biasing conditions. The channel current initially decreases slightly with a decrease in node size (10 nm) due to an increase in channel resistance but at 5 nm it increases sharply due to reduction in self-heating, channel leakage and short channel effect. Under the sub threshold regime, large leakage in channel current has been seen in nodes with smaller gate size and higher fin numbers. Multi-fin nodes have also shown an increase in drain current and a decrease in device temperature with fin number, due to the large area for dissipating heat and channel leakage. On the other hand, the GAA structure shows better channel control, less leakage and lower self-heating. In GAA nodes the channel current can be further increased by increasing the number of channels and thus, upholding their importance for microelectronics and high-speed electronics at 5 nm and below.