Advantages
- The silicide electrode’s contact resistivity can be reduced by one order of magnitude.
- This method can be applied to various silicide electrodes, aiming to improve contact performance.
Background and Technology
In semiconductor devices such as MOSFETs, silicide films are used for gate and source/drain electrodes on Si substrates, which are obtained by annealing of metal film formed on a Si substrate by reaction of Si and the metal film. One of the problems in silicide film formations is that oxidation of the metal surface during annealing process, which deteriorates the surface morphology and increases electrical resistance. As a solution to this problem, a method has been proposed; to form a thin film of another compound (cap layer) on the metal film to be silicide before annealing to suppress oxidation.
With recent miniaturization of semiconductors, there is a requirement to improve the performance of silicide thin films and their electrodes.
Associate Professor Shun-ichiro Ohmi of Tokyo Institute of Technology has discovered that Hf compounds (HfN, HfW, etc.) are useful as a cap layer because of their high barrier performance in developing silicide films and electrodes that meet semiconductor miniaturization requirements. In particular, HfN has the advantages in selective etching and easy handling.
Data
- The RMS of the PtSi film measured by AFM was 2.26 nm when HfN was used as the cap film, while it was 3.12 nm when no cap layer was used.
- After forming a CBKR (Cross-Bridge Kelvin Resistor) structure in PtSi alloy film, the contact resistivity was measured under annealing conditions in an N2/4.9% H2 When using HfN as the cap layer, the contact resistance was 4.8 × 10-7 Ωcm2, whereas without applying the cap layer, it was 4.9 × 10-6 Ωcm2.
Patents
- Patent granted: JP.6086550, TW.I609415
Principal Inventor
Shun-ichiro Ohmi (Associate Professor, Tokyo Institute of Technology)
Next Step
- Tech Manage is now looking for a company to research and develop semiconductor devices by licensing or collaborate with us on this technology.
- Meeting (including web meeting) with the inventor, Associate Professor Ohmi, is available.
Project No. MO-04698