The Impact of Ambient Temperature on Electrothermal Characteristics in Stacked Nanosheet Transistors with Multiple...

With characteristic size scaling down to the nanoscale range, the confined geometry exacerbates the self-heating effect (SHE) in nanoscale devices. In this paper, the impact of ambient temperature (T_amb) on the SHE in stacked nanosheet transistors is investigated. As the number of lateral stacks (N_stack) increases, the nanoscale devices show more severe thermal crosstalk issues, and the current performance between n- and p-type nanoscale transistors exhibits different degradation trends. To compare the effect of different T_amb ranges, the temperature coefficients of current per stack and threshold voltage are analyzed. As the N_stack increases from 4 to 32, it is verified that the zero-temperature coefficient bias point (V_ZTC) decreases significantly in p-type nanoscale devices when T_amb is above room temperature. This can be explained by the enhanced thermal crosstalk. Then, the gate length-dependent electrothermal characteristics with different N_stacks are investigated at various T_ambs. To explore the origin of drain current variation, the temperature-dependent backscattering model is utilized to explain the variation. At last, the simulation results verify the impact of T_amb on the SHE. The study provides an effective design guide for stacked nanosheet transistors when considering multiple stacks in circuit applications.