Monolithic 3D-ICs with single grain Si thin film transistors

We review our achievement in monolithic 3D-ICs based on single-grain Si TFTs that are fabricated inside a single-grain with a low-temperature process. With pulsed-laser crystallization, Si grains with a diameter of 6 μm are successfully formed on predetermined positions. Single-grain (SG) Si TFTs are fabricated inside the single-grain with mobility for electron and holes of 600 cm
²
/Vs and 200 cm
²
/Vs, respectively. Using two layers of the SG Si TFT layers, CMOS inverter, 6T-SRAM and image sensor array with in-pixel amplifier have been fabricated.