Germanium Nanowire Metal-Oxide-Semiconductor Field-Effect Transistor Fabricated by Complementary-Metal-Oxide-Semiconductor-Compatible Process

• Published in: IEEE transactions on electron devices 2011-01, Vol.58 (1), p.74-79
• Main Authors: Peng, J W, Singh, N, Lo, G Q, Bosman, M, Ng, C M, Lee, S J
• Format: Article
• Language: English
• Subjects: Applied sciences; Core/shell (C/S); Cross-disciplinary physics: materials science; rheology; Design. Technologies. Operation analysis. Testing; Devices; Electronics; Epitaxial growth; Epitaxy; Etching; Exact sciences and technology; Germanium; germanium (Ge); Integrated circuits; Logic gates; Materials science; metal-oxide-semiconductor field-effect transistor (MOSFET); MOSFET circuits; MOSFETs; Nanocomposites; Nanomaterials; Nanoscale materials and structures: fabrication and characterization; nanowire (NW); Nanowires; Physics; Quantum wires; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Shells; Silicon; top-down; Transistors; Wire
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2010.2088125

This work presents a complementary metal-oxide-semiconductor-compatible top-down fabrication of Ge nanowires along with their integration into pMOSFETs with "HfO 2 /TaN" high-k/metal gate stacks. Lateral Ge wires down to 14 nm in diameter are achieved using a two-step dry etch process on a high-quality epitaxial Ge layer. To improve the interface quality between the Ge nanowire and the HfO 2 , thermally grown GeO 2 and epitaxial-Si shells are used as interlayers. Devices with a GeO 2 shell demonstrated excellent I ON /I OFF ratios (>; 10 6 ), whereas the epitaxial-Si shell was found to improve the field-effect mobility of the holes in Ge nanowires to 254 cm 2 V -1 · s -1 .