Direct molybdenum contacts to silicon

Stringent requirements on the electrical and metallurgical properties of metallization systems for use in advanced, very large scale integrated circuits have created the need to study new metal‐silicon systems. We have conducted a study of the Mo/Si direct contact system. The choice of molybdenum stems from its desirable electrical and metallurgical properties. To date, however, its contact properties to silicon were not examined in detail. Results of the present study show that Mo can result in low resistivities (<5 Ω μm²) for both contacts to heavily doped p⁺‐Si and n⁺‐Si, provided appropriate care is taken in opening the contact windows. Further, we found the Mo/Si contact system to be stable under extended heat treatments at temperatures of up to 650 °C.