Low-temperature epitaxial SiGe:P for gate-all-around n-channel metal-oxide-semiconductor devices

Abstract

This study investigates the viability of Si1-xGex:P (x <= 0.3) as a novel source/drain material for n-channel Metal-Oxide-Semiconductor for Gate-All-Around (GAA) transistors, addressing the challenges posed by the evolving semiconductor technology. Utilizing a reduced-pressure chemical vapor deposition system, undoped SiGe with low Ge contents were grown at temperatures of <= 500 degrees C. The addition and optimization of phosphorous doping using phosphine results in improved surface morphology and increased active carrier concentration. The study compares Si1-xGex:P with different silicon precursors and temperatures, emphasizing the potential for maintaining high growth rates at lower temperatures when using Si3H8. Ti/Si1-xGex:P stacks reveal a promising reduction in contact resistivity with decreasing the Ge content, particularly when incorporating thin Si:P cap layers at the Ti/Si1-xGex:P interface. This comprehensive study highlights the potential of Si1-xGex:P as an alternative material for advanced GAA transistor technologies, offering improved mobility and meeting the thermal budget requirements. (c) 2024 The Japan Society of Applied Physics. All rights, including for text and data mining, AI training, and similar technologies, are reserved.