Low-Temperature Recrystallization and Contact Process Technology for 3D Sequential Integration

In this paper, low-temperature (LT) recrystallization technology and silicide contact process for 3D sequential integration (3DSI) were demonstrated, respectively. The NiSi 2 -seed initiated lateral epitaxial crystallization (SILEC) was presented to obtain high-quality crystalline-like Si channel for top-level device fabrication. The nanowire FET (NWFET) by SILEC exhibits ideal subthreshold swing (~ 64 mV/dec) and high hole mobility (~ 49.5 cm ² /(V•s)) owing to the epitaxy nature of SILEC process. By combining LT molecular beam epitaxy (MBE) and two-step anneal scheme, ultra-thin NiSi 2 formed on the in-situ doped Si: P substrate with a high doping concentration of 1.2×10 ²¹ cm ⁻³ under a low thermal budget (≤ 450 °C). The record low contact resistivity (4.6 × 10 ⁻⁹ Ω•cm ² ) is obtained at the low temperature. Those LT process modules will be good performance boosters for the future 3DSI technology.