Strained Thin-Body p-MOSFET With Condensed Silicon-Germanium Source/Drain for Enhanced Drive Current Performance

• Published in: IEEE electron device letters 2007-06, Vol.28 (6), p.509-512
• Main Authors: Kah-Wee Ang, King-Jien Chui, Madan, A., Lai-Yin Wong, Chih-Hang Tung, Balasubramanian, N., Ming-Fu Li, Samudra, G.S., Yee-Chia Yeo
• Format: Article
• Language: English
• Subjects: Applied sciences; Band structure of solids; Capacitive sensors; CMOS technology; Computational modeling; Condensing; D region; Devices; Drains; Electronics; Etching; Exact sciences and technology; Ge condensation; Germanium; Germanium silicon alloys; MOSFET circuits; Oxidation; p-MOSFETs; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon germanides; Silicon germanium; Silicon on insulator technology; Silicon substrates; silicon-germanium (SiGe); strain; Strain control; Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2007.896802

Strained p-MOSFETs with silicon-germanium (SiGe) source and drain (S/D) stressors were fabricated on thin-body silicon-on-insulator (SOI) substrate using a novel local oxidation or Ge condensation technique. By directly growing SiGe on the S/D regions and followed by a local Ge condensation process, the challenges imposed on Si recess etch on thin-body SOI substrates can be alleviated. In the Ge condensation step, the Ge content in the S/D regions may also be increased. At a gate overdrive of -1 V, strained p-MOSFETs show an enhancement in the saturation drive current I on of up to 38% over the control p-MOSFETs. This significant I on enhancement is attributed to strain-induced band structure modification, which reduces the hole effective mass along the transport direction. The improved series resistance of the strained devices with SiGe S/D accounted for approximately one-third of the I on enhancement.