SOI MOSFET modeling using an AC conductance technique to determine heating

Steady-state and dynamic thermal models for heat flow analysis of silicon-on-insulator MOSFETs

“…Inclusion of self-heating effects in SOI industry is usually based on the oversimplified thermal circuit with a ST node [17][18][19][20][21]37]. Some approaches derived from the assumption of constant channel temperature or uniform power generation in the channel have been reported in recent studies [22][23][24].…”

“…Because of the thin silicon island, a 1D temperature distribution is assumed in the silicon film; namely, T Si ¼ T Si ðx; tÞ. Instead of using the SOI channel thermal resistance R thc [18][19][20][21][22][23][24], the film thermal resistance R thf introduced in [25,27] is used to describe the heat loss from the film to the substrate through BOX and FOX, which is defined as…”

“…With T fox ðx; yÞ, given in Eq. (19), the heat transfer coefficient for heat conduction from the silicon to FOX can be derived from Àj ox oT fox ðx; yÞ ox…”

“…Less attention has been paid to thermal behavior in devices. Studies of self-heating or thermal behavior in devices usually treat the devices as single heat sources without temperature variation inside the devices [15][16][17][18][19][20][21].…”

“…It has been found that the channeldrain junction temperature is usually considerably higher than the source/drain temperature. Device reliability predicted based on constant channel/device temperature, such as the single temperature (ST) node thermal circuit [17][18][19][20][21] widely used in the industry, may be substantially different from that taking into account the large temperature gradient in the SOI channel. Due to the large temperature gradient, heat flow from the gate, source or drain to the poly-line or interconnects may be significantly different.…”