Hybrid integrated Si nanosheet GAA-FET and stacked SiGe/Si FinFET using selective channel release strategy

A hybrid integration scheme of Si nanosheet (NS) gate-all-around (GAA) field-effect transistor (FET) and stacked SiGe/Si FinFET is explored in detail. Si NS GAA-FET can provide excellent electrical performance as gate length (LG) is no more than 100 nm. However, when LG of Si NS GAA-FET exceeds 100 nm, NS will suffer from the deformation problem due to insufficient mechanical strength and the large liquid surface tension during channel release process, which causes deterioration of electrical performance fluctuations. With the introduction of the selective channel release (SCR) strategy, the stacked SiGe/Si FinFET with excellent and uniform electrical per-formance is achieved for long-channel device. This is attributed to its complete immunity to NS deformation due to the absence of SiGe sacrificial layer release. Therefore, this hybrid integration strategy is critical to boosting the manufacturability of various gate length in the SoC integrated circuit.