High hole mobility in Si0.17Ge0.83 channel metal–oxide–semiconductor field-effect transistors grown by plasma-enhanced chemical vapor deposition

Abstract

We report on effective hole mobility in SiGe-based metal–oxide–semiconductor (MOS) field-effect transistors grown by low-energy plasma-enhanced chemical vapor deposition. The heterostructure layer stack consists of a strained Si0.17Ge0.83 alloy channel on a thick compositionally-graded Si0.52Ge0.48 buffer. Structural assessment was done by high resolution x-ray diffraction. Maximum effective hole mobilities of 760 and 4400 cm2/Vs have been measured at 300 and 77 K, respectively. These values exceed the hole mobility in a conventional Si p-MOS device by a factor of 4 and reach the mobility data of conventional Si n-MOS transistors.

Hole mobility enhancement of p-MOSFETs using global and local Ge-channel technologies

“…Fig. 8 shows the mobility enhancement factor of fabricated surface-channel SGOI p-MOSFETs (open and closed circles) [13,14] as well as that of buried channel devices (open triangles) [15][16][17], previously reported. The results of Raman spectroscopy show that the thick SGOI p-MOSFETs with Ge content ranging from 77 to 93% (closed circles) are partially relaxed (−ε = 0.7-1.5%) and the thin SGOI p-MOSFETs with Ge content ranging from 48 to 59% (open circles) are fully compressive strained (−ε = 2.0-2.5%).…”

“…By locally oxidizing SiGe layers on SOI substrates as similar with the LOCOS isolation, SGOI or pure GOI channel regions can be formed selectively in the active area of p-MOSFETs. One of the advantages of this local Ge [15][16][17]. The solid and dash lines mean the calculated results with and without strain (1.5%), respectively [18].…”

Erbium silicidation on SiGe for advanced MOS application

“…Due to the low Schottky-barrier-height (SBH) and its relatively low resistivity [2 -4], rare earth metal (especially Erbium) silicides have become promising candidates for advanced MOS applications such as Schottky CMOS. Study of rare earth germanosilicides growth on SiGe substrate has received some attention recently due to its ability to improve transistor performance [5]. While the formation of ErSi 2 through the reaction between Er and Si substrate usually results in the formation of pits and defects which affects the barrier height as well as the reverse current [6,7], little is known about the resulting structure from the reaction between Er and Si 1Àx Ge x substrate.…”

Hole mobility enhancements in nanometer-scale strained-silicon heterostructures grown on Ge-rich relaxed Si1−xGex

“…[19][20][21] In these devices, termed dual-channel heterostructures, a compressively strained Si 1Ϫy Ge y layer is grown upon a relaxed Si 1Ϫx Ge x buffer (yϾx) and capped with tensile ⑀-Si. The large hole mobility enhancements in these structures is attributed to the following factors: first, compressive strain splits the valence band degeneracy and reduces the in-plane and out-of-plane effective masses in a manner analogous to tensile strain.…”