Thick-Strained-Si/Relaxed-SiGe Structure of High-Performance RF Power LDMOSFETs for Cellular Handsets

• Published in: IEEE transactions on electron devices Vol. 53; no. 12; pp. 3136 - 3145
• Main Authors: Kondo, M., Sugii, N., Hoshino, Y., Hirasawa, W., Kimura, Y., Miyamoto, M., Fujioka, T., Kamohara, S., Kondo, Y., Kimura, S., Yoshida, I.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-12-2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Laterally diffused MOSFETs (LDMOSFETs); misfit dislocations; power amplifiers; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SiGe; strained-silicon; Transistors; Performance evaluation; Semiconductor alloys; High performance; MOSFET; Mobile phone; Lateral diffusion; Thermal behavior; strained-silicon; Misfit dislocation; SiGe; Code division multiple access; misfit dislocations; Radiofrequency amplifiers; Self heating; power amplifiers; Power amplifier; Laterally diffused MOSFETs (LDMOSFETs)
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2006.885669

A strained-Si/relaxed-SiGe structure was applied to laterally diffused MOSFETs (LDMOSFETs) in order to improve the PAE of cellular handset RF power-amplifier applications. The LDMOSFETs were fabricated in a 70-nm-thick strained-Si/relaxed-Si 0.85 Ge 0.15 structure. Despite the appearance of misfit dislocations, the thick strained-Si was essential for high efficiency and low leakage. The self-heating effects on the power performance were estimated to be negligible by using dynamic thermal simulation. The devices exhibited 46.6% PAE at a P out of 27.5 dBm for wideband code-division multiple-access handset applications, which was a 3.8-point improvement over Si controls