Rectifying characteristics of sputter-deposited SiGe diodes

Abstract

Schottky and pn junction diodes with good rectifying characteristics have been prepared based on the polycrystalline SiGe (poly-SiGe) thin film deposited by the ion-beam-sputtering (IBS) technique. Boron and phosphorus diffusion techniques have been used to dope and crystallize as-deposited amorphous SiGe film. Rectification ratios as high as 4000 and 1800 have been achieved in Pt/n-poly-SiGe and Ti/p-poly-SiGe Schottky diodes, respectively, while rectification ratio higher than 1500 and breakdown voltage higher than 200 V have been achieved in poly-SiGe pn junction diodes. Schottky barrier height has been determined to be 0.62 and 0.59 eV for Pt/n-poly-Si0.81Ge0.19 and Ti/p-poly-Si0.81Ge0.19 contacts, respectively, which indicates that the band alignment of poly-SiGe may be substantially different from that of epitaxial SiGe.

Schottky contact properties of Ni/n-poly-Si0.87Ge0.13/n-Si(100) heterostructure

“…To our knowledge, little work has been done on metal/poly-SiGe contacts properties so far. Recently, we demonstrated excellent rectifying characteristics of Pt and Ti on poly-Si 0.8 Ge 0.2 without annealing treatment [12]. However, in many potential application cases, the contact properties of an annealed structure are more important than those of an unannealed structure.…”

Fabrication of poly-Si TFT with silicided Schottky barrier source/drain, high-κ gate dielectric and metal gate

“…In the TFT case, the device electrical performance may be also improved if the barrier height between the silicide source and poly-Si channel is reduced. Even though the knowledge about the Schottky barrier of silicide/poly-Si contacts is lack, it is expected that silicide on poly-Si has similar barrier height as that on single crystalline Si [14]. We recently developed a simplified low temperature SSDT process on single crystalline Si using self-aligned PtSi (for PMOS) and DySi 2Àx (for NMOS) S/D, HfO 2 gate dielectric and TaN/HfN metal gate electrode [15].…”