The thermal endurance and microstructural evolution of Ni-germanide (NiGe) and Pt-germanide (PtGe) on a Ge-on-Si substrate were compared in this paper. In case of the Ni/TiN structure, the sheet resistance exhibited a stable RTP window of 350 to 600 °C, while that of the Pt/TiN structure showed more stable characteristics up to 700 b C. Furthermore, after post-germanidation annealing, NiGe exhibited the formation of islands due to the severe agglomeration as well as a prominent grain boundary grooving, which accounts for the sharp increase of the sheet resistance from 550 °C, whereas PtGe showed a smooth and continuous surface morphological stability without signs of agglomeration even up to 600 °C. Although about two times higher resistivity (31.5 yufl-cm) and greater Ge consumption (3.27 nm) were shown, PtGe showed more stable sheet resistance, better surface and interface morphological stability and a wider thermal processing window above 100 °C than NiGe. Therefore, PtGe is more suitable for the germanided shallow source/drain for nano-scale Ge MOSFETs than NiGe.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics