Ge (100) and (111) N- and P-FETs With High Mobility and Low- T Mobility Characterization

• Published in: IEEE transactions on electron devices Vol. 56; no. 4; pp. 648 - 655
• Main Authors: Kuzum, D., Pethe, A.J., Krishnamohan, T., Saraswat, K.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-04-2009; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Conductance; Density; Dielectrics; Electron mobility; Electronics; Exact sciences and technology; Gates; Germanium; interface state density extraction; Logic gates; mobility; MOS devices; MOSFET; Orientation; Photonic band gap; Scattering; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Substrates; Temperature measurement; Transistors; Temperature distribution; Interface state; MOSFET; Density of states; mobility; orientation; Hole mobility; PMOS technology; n channel; interface state density extraction; Temperature measurement; Field effect transistor; Charge carrier scattering; scattering; Electron mobility; Germanium; NMOS technology
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2009.2014198

In this paper, we demonstrate high-mobility bulk Ge N- and P-FETs with GeON gate dielectric. The highest electron mobility to date in Ge is reported, and two times improvement over universal hole mobility is achieved for Ge P-FETs. For the first time, the effect of surface orientation on Ge mobility is investigated experimentally. A 50% improvement in electron mobility is shown for the (111) substrate orientation compared to the (100) orientation. Carrier scattering mechanisms are studied through low-temperature mobility measurements and interface characterization. The conductance technique is applied at low temperatures for complete mapping of the density of interface traps (D it ) across the Ge bandgap and also close to the band edges. Carrier scattering mechanisms and the distribution of D it are compared for Ge NMOS and PMOS.