Silicides for the 65 nm Technology Node

Abstract

At the 65 nm node, silicide faces formidable challenges. Co is the current process of record for most integrated circuit manufacturers and thus becomes baseline silicide for 65 nm. However, Ni is the likely replacement. Both silicides are challenged to meet the requirements at the 65 nm node. This manuscript reviews the current CoSi2challenges (dopant interactions, Ge interactions, linewidth extendibility, impurity effects, agglomeration issues, etc). Ni consumes less Si but has its own challenges, including issues with contact leakage and thermal budget, excessive diffusion and oxidation, interactions with dopant and impurities. Both silicides have formation and stability issues in the presence of Ge. Additions of Ge increase the temperature at which a low resistance CoSi2is formed due to film segregation into CoSi2and Ge-rich Si-Ge grains. With Ni, additions of Ge decrease the temperature at which NiSi converts to a NiSi2, lead to agglomeration at a lower temperature and lead to germanosilicide formation.

Two-Dimensional Semiconductors and Transistors for Future Integrated Circuits

“…Many alternative approaches in terms of materials and structures have been proposed to alleviate performance deterioration, − as shown in Figure . In the 90 nm node, strained silicon technology is introduced to modulate the band structure of the Si channel, thereby enhancing carrier mobility. , Furthermore, the adoption of a high-κ dielectric and metal gate (HKMG) has advanced the process technology to a 45 nm node. , The scaling of high-κ HfO 2 instead of SiO 2 is beneficial to reducing leakage current while maintaining gate controllability.…”

“…Since the 22 nm node, the gap between the gate length and technology node has become increasingly wide. The gate length values are from refs , , and − . For further scaling of transistors, post-Moore electronics, which are primarily based on atomic-scale materials and unconventional devices and architectures, will be an important driving force for future integrated circuits.…”

Moore’s Law for Photonics and Electronics

“…In 65 nm technology node and beyond, Ni was chosen as an outstanding metal for silicides for CMOS structure [35]. NiSi has several advantages compared to other silicides, e.g., TiSi 2 and CoSi 2 including low sheet resistance on narrow lines as well as low-temperature process with low silicon consumption as given in Table 4.2 [36].…”

Silicides for 22nm and Beyond

“…Ge is introduced to the active regions by selective epitaxial growth, in which the Ge replaces Si substitutionally. Although additions of Ge on the order of 20-30% are common, it is difficult to form a low resistance phase in the presence of Ge [4][5][6][7]. CoSi 2 has difficulty forming on Si-Ge substrates [6,[8][9][10], while Ni or NiPt do form a low resistance phase that is much more sensitive to both chemical attack and degradation upon annealing.…”