Abstract

 In this work, we first demonstrated heterogeneous 3D (H3D) sequential complementary field-effect transistors (seqCFETs) highlighting biaxially compressively strained Ge (100) (sGe) channel, which

potentially solves a critical bottleneck in CFET development: high mobility top strained p-channel limited by the difficulty of SiGe stressor growth. Leveraging high-quality heteroepitaxial growth and direct wafer bonding (DWB), we achieved ~0.6% biaxially compressively sGe on a 6-inch Si wafer by growing Ge virtual substrate, Si0.5Ge0.5 stressor/etch stopper, and sGe channel layer. Finally, we first demonstrated the H3D seqCFET with biaxially compressively sGe (100) p-channel metal-oxide-semiconductor FETs (MOSFETs), featuring good voltage transfer curve (VTC) characteristics with high voltage gain (Vgain) of 51 V/V at supply voltage (VDD) = 1.25 V. We believe that the sGe channel realized by the method shown in this work will be a very promising technology to realize high-performance vertically 3D stacked CFET in the future.