Thermodynamic analysis based on first-principles calculations were performed for SiHxCl4-x (x = 0~3) to compare characteristics of these chlorosilanes. In the range of 600-1100°C, SiCl4 almost does not decompose, while SiHCl3, SiH2Cl2, and SiH3Cl decompose and generate SiCl2 as main radical species. SiHCl3 and SiH2Cl2 have 3.8 and 4.5 times higher SiCl2 equilibrium partial pressure than SiH3Cl at 600°C, respectively. SiH3Cl has lower equilibrium partial pressure of HCl than SiHCl3 and SiH2Cl2 by order level. Thus, it is expected that CVD using SiH3Cl gas is less affected by HCl reaction.

To obtain the fundamental understanding on the capability to apply the Zr film to Al metallization technology for Si‐LSI, interfacial solid‐phase reactions in Al/Zr/Si, Al‐Zr/Zr/Si, and Al3Zr/Zr/Si contact systems have been investigated by AES analysis. In the Al/Zr/Si system, Al and Zr layers reacted spontaneously and interdiffused each other even before the heat treatment. In the Al‐Zr/Zr/Si system, in which the Al overlayer was replaced with the Zr‐doped Al film, well‐separated interfaces of Al‐Zr/Zr and Zr/Si were observed before the heat treatment. But when heat treated at 400°C, Zr atoms in the Zr layer migrated into the Al‐Zr overlayer and the interposed Zr layer became too thin prior to the formation of the distinct Zr silicide layer. In the Al3Zr/Zr/Si system, the amorphous overlayer with the composition of Al3Zr recrystallized into a stable Al3Zr intermetallic compound during the heat treatment above 400°C. In this system, because the thermal equilibrium state is realized at the Al3Zr/Zr interface, a possible solid‐phase reaction is restricted only at the Zr/Si interface. Therefore, the system tolerates the temperatures up to 500°C and a stable Zr‐silicide layer can be formed at the Zr/Si interface.