First Demonstration of Low Temperature (≤500°C) CMOS Devices Featuring Functional RO and SRAM Bitcells toward 3D VLSI Integration

Abstract

For the first time FDSOI CMOS transistors with Si-monocrystalline channel have been fabricated at a temperature below 500°C. High performance PMOS (Ion=450μA/μm (Vdd −0.9V) @ Ioff=2nA/μm Lg=35nm) with low overlap capacitance (0.46fF/μm per device), low gate resistance (10Ω) at Low Temperature (LT) enables to achieve good RF Figure-Of-Merit (FOM) with Fmax values up to 170GHz. In addition, we demonstrate for the first time the full functionality of Ring Oscillators (RO) and SRAM bitcells processed at 500°C, paving the way for a high-performance 3D sequential CMOS integration.