Very High Carrier Mobility for High-Performance CMOS on a Si(110) Surface

• Published in: IEEE transactions on electron devices Vol. 54; no. 6; pp. 1438 - 1445
• Main Authors: Teramoto, A., Hamada, T., Yamamoto, M., Gaubert, P., Akahori, H., Nii, K., Hirayama, M., Arima, K., Endo, K., Sugawa, S., Ohmi, T.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Alkaline cleaning; Applied sciences; Balancing; Channel; Cleaning; CMOS; CMOS integrated circuits; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Flattening; flicker; High speed; Integrated circuits; Logic gates; mobility; MOSFET; MOSFET circuits; MOSFETs; noise; Oxidation; Radicals; roughness; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; surface orientation; Surface treatment; Transistors; High performance; MOSFET; mobility; Low noise circuit; flicker; Surface current; Charge carrier mobility; Roughness; Channel; surface orientation; Mixed signal circuit; n channel; Mixed analogue-digital integrated circuits; Cleaning; 1/f noise; Implementation; CMOS; p channel; Complementary MOS technology; noise; Oxidation; Room temperature
• DOI: 10.1109/TED.2007.896372
• ISSN: 0018-9383

In this paper, we demonstrate CMOS characteristics on a Si(110) surface using surface flattening processes and radical oxidation. A Si(110) surface is easily roughened by OH - ions in the cleaning solution compared with a Si(100) surface. A flat Si(110) surface is realized by the combination of flattening processes, which include a high-temperature wet oxidation, a radical oxidation, and a five-step room-temperature cleaning as a pregate-oxidation cleaning, which does not employ an alkali solution. On the flat surface, the current drivability of a p-channel MOSFET on a Si(110) surface is three times larger than that on a Si(100) surface, and the current drivability of an n-channel MOSFET on a Si(100) surface can be improved compared with that without the flattening processes and alkali-free cleaning. The 1/f noise of the n-channel MOSFET and p-channel MOSFET on a flattened Si(110) surface is one order of magnitude less than that of a conventional n-channel MOSFET on a Si(100) surface. Thus, a high-speed and low-flicker-noise p-channel MOSFET can be realized on a flat Si(110) surface. Furthermore, a CMOS implementation in which the current drivabilities of the p-channel and n-channel MOSFETs are balanced can be realized (balanced CMOS). These advantages are very useful in analog/digital mixed-signal circuits.