A Physics Based Thermal Circuit Model for FinFETs
Paul Russell, Ming-Cheng Cheng
Electrical and Computer Engineering
The FinFEt is a multigate transistor, a strategy being developed by semiconductor manufacturers to
overcome short channel effects in traditional planar transistors to create smaller microprocessors and
memory cells. Due to the geometry of the FinFET the heating problem has dramatically increased. Selfheating in the FinFET results in degradation in overall device performance. It is therefore crucial for chip
designers to consider thermal influences on device/interconnect/chip performance and their reliability. A
typical Integrated Circuit (IC) chip consists of millions of transistors, making direct numerical simulation
impractical. Accurate thermal models for the FinFET that is detailed enough to provide the device
temperature profile and efficient enough for large scale electro-thermal simulation are therefore strongly
desirable. In order to model the heat flow through the FinFET, the island is divided into uniform regions
and for each interface between adjacent regions temperature and heat flux continuities are applied. Due to
the uniform power generation along the device width direction, the problem of heat flow along the thin
island is reduced to a 1D problem if the heat flow out of the island is treated as losses. Once the solution
in each region is obtained, a thermal circuit can be derived for the FinFETs. The thermal circuit was used
to generate the temperature profile along the device without the gate. When compared to finite element
simulations the error was fairly small. Results are still preliminary, however, they show promise for
creating an efficient model to provide accurate temperature profiles.
2011, Electrical Engineering, Honors Program, Dr. Ming-Cheng Cheng