Thermal Stability Concern of Metal-Insulator-Semiconductor Contact: A Case Study of Ti/TiO₂/n-Si Contact

Abstract

This work discusses the thermal stability of metal-insulator-semiconductor (MIS) contacts. A case study is performed on a typical low-Schottky barrier height (qϕ b ) MIS contact: Ti/TiO 2 /n-Si. By incorporating different levels of donor concentration in n-Si, we perform a systematic Ti/TiO 2 /n-Si thermal stability study under different electron conduction mechanisms. We find that both qϕ b and contact resistivity (ρ c ) of the Ti/TiO 2 /n-Si MIS contacts vary dramatically after mere 300°C-500°C 1-min rapid thermal treatments. The variations in qϕ b and ρ c are related to the thermally driven TiO 2 decomposition. This thermal stability study of Ti/TiO 2 /n-Si reveals a general concern for the MIS contact application: since the MIS contacts on n-type semiconductor generally utilize a reactive low-work function metal and an ultrathin insulator, it is difficult to maintain their interface quality considering the thermal budget in standard manufacturing of integrated circuits. Possible solutions to this MIS thermal stability issue are discussed.

A Plasmonic quantum dot nanolaser: effect of “waveguide Fermi energy” on material gain

“…The results obtained here were coinciding with the conclusion of [25]. They find experimentally that when metal/semiconductor contact resistivity was reduced the performance was improved.…”

“…Schottky barrier heights (qϕ m ) must be reduced to get a low resistivity. Pinning Fermi-level close to VB in this work stiffs the low (qϕ m ) [25].…”

Scaling Challenges for Advanced CMOS Devices

“…This induces a Schottky Barrier Height shift to offset the pinned electron barrier height. Reported data in the literature suggest that the concept of MIS or tunneling contacts could potentially help to reduce R silicide-con further but it is not without its integration challenges such as the thermal stability of the dielectric 122 and/or applicability of this concept to highly doped semiconductors 123,124,125,126 .…”

Highly Reliable Contacts to Silicon Enabled by Low Temperature Sputtered Graphenic Carbon

“…The low barrier height makes TiSi very promising for further contact resistance reductions to NMOS and PMOS devices [6], [7]. However, titanium-based contacts exhibit a low thermal stability [8], [9], which is not suitable for increased Joule heating by large current densities in downscaled devices.…”