Formation of Very Low Contact Resistance between Metal and Semiconductor using Semiconductor Structures with Ultra High Carrier Concentration

本研究采用原子控制低压化学气相沉积(LP-CVD)技术在SiGEC异质结中掺入重杂质(B和P)，使金属与半导体形成极低的接触电阻。利用原子控制的低压化学气相沉积(LP-CVD)技术在Si(100)和Ge(100)上实现了氢化物气体(PH_3和B_2H_6)在Si(100)和Ge(100)表面的热吸附和反应中形成1-3个第IV族原子层或相关原子层。采用原子层掺杂技术制备了杂质浓度大于10^&lt；21&gt；cm^&lt；-3的重杂质掺杂外延硅薄膜。通过在P掺杂的SiGe薄膜上生长高载流子浓度的多层P掺杂外延硅，在很低的温度下获得了6.5×10~(-8)&gt；Ωcm^2的W与Si薄膜的接触电阻率。对于高载流子浓度的B掺杂SiGEC薄膜，W与Si薄膜的接触电阻率为3.8×10~(-8)Ωcm^2，Ti与Si薄膜的接触电阻率为3×10~(-8)Ωcm^2，这种重杂质掺杂技术有望实现高性能半导体器件中金属与半导体之间的极低接触电阻。

In this research, heavily impurities (B and P) were doped in SiGeC heterostructure using atomically controlled low-pressure chemical vapor deposition (LP-CVD) in order to form a very low contact resistance between metal and semiconductor.Formation of 1-3 atomic layers of group IV or related atoms in the thermal adsorption and reaction of hydride gases (PH_3 and B_2H_6) on Si(100) and Ge(100) have been achieved using atomically controlled ultraclean LP-CVD. Heavily impurity doped epitaxial Si films with the impurity concentration of over 10^<21>cm^<-3> are formed by an atomic-layer doping technique. By growing the multi-layer P-doped epitaxial Si with a high carrier concentration at a very low temperature of 450℃ on the P-doped SiGe films, very low contact resistivity of 6.5x10^<-8>Ωcm^2 between W and the Si film has been obtained. For the B-doped SiGeC films with a high carrier concentration, very low contact resistivity is obtained to be 3.8x10^<-8>Ωcm^2 between W and the Si film, 3x10^8<-8>Ωcm^2 between Ti and the Si film.This heavily impurity-doping technique promises to achieve very low contact resistance between metal and semiconductor for high performance semiconductor devices.