Formation of thin Ni2Si and NiSi films using low temperature rapid thermal processing

The ultra-thin nickel silicide films were grown using both soak and spike anneals from temperatures from 160°C to 400°C in 10-20°C intervals as a means to characterize the low temperature annealing capabilities of our RTP system. The Rs transformation curves were generated and the resulting films were characterized by Rs and xTEM. A ~5 nm Ni₂Si film is formed at 160C from a starting material of 10 nm Ni film capped with 10 nm TiN layer on a <100> silicon substrate. The film from a 200°C soak anneal on the same stack, followed by excess Ni strip and 400°C RTA2 yielded a < 10 nm NiSi film with an Rs of ~30 ¿/¿. The RTP system used to form the ultra-thin nickel silicide films extends the low temperature processing down to at least 50°C on Si substrates. This enables spike and soak anneals at any processing temperatures starting from temperatures greater than 50°C without impacting the high temperature performance of the chamber. Due to the setup simplicity and uniform heating from multiple-point closed-loop temperature control, this speeds up recipe startup as well as shortens recipe execution time, thus improving the anneal throughput.