Electron transport properties of Si/SiGe heterostructures : measurements and device implications

• Published in: Applied physics letters 1993-08, Vol.63 (5), p.660-662
• Main Authors: ISMAIL, K, NELSON, S. F, CHU, J. O, MEYERSON, B. S
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Physics
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.109949

We report electron transport properties of modulation-doped Si/SiGe at 300 and 77 K. Record mobilities of 2830 and 18 000 cm2/V s at 300 and 77 K, respectively, have been measured. Depending on the spacer layer thickness, the sheet resistance of the Si channel is in the range of 2000–10 000 Ω/⧠ at 300 K and 450–700 Ω/⧠ at 77 K. The low field electron drift velocity is 2–3 (5–10) times higher than the corresponding velocity measured in Si/SiO2 structures at 300 K (77 K). The saturation velocity is measured to be only 5% higher than in bulk Si, at both 300 and 77 K, but appears at a lower electric field. The effect of the enhanced transport properties in modulation-doped Si/SiGe on device design and performance is investigated.