About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Thin Solid Films
Paper
High strain embedded-SiGe via low temperature reduced pressure chemical vapor deposition
Abstract
Performance improvement of strained p-type metal oxide semiconductor field effect transistors (p-MOSFETs) via embedded SiGe (e-SiGe) is well established. Strain scaling of p-MOSFETs since 90 nm complementary metal oxide semiconductor node has been accomplished by increasing Ge content in e-SiGe from nominally < 20% in 90 nm p-MOSFETs to > 35% Ge in 32 nm p-MOSFETs. Further strain enhancement for 22 nm and beyond p-MOSFETs is required due to disproportionate reduction in device area per generation caused by non-scaled gate length. Relaxation of SiGe with > 35% Ge during epitaxial growth and subsequent processing is a major concern. Specifically low temperature growth is required to achieve meta-stable pseudomorphic SiGe film with high Ge%. Currently, selective SiGe epitaxial film in reduced pressure chemical vapor deposition (RPCVD) epitaxy is grown with conventional Si gas precursors and co-flow etch using HCl at temperatures higher than 625 °C. At temperatures lower than 625°C in RPCVD epitaxy, however, HCl has negligible etch capability making selectivity difficult to achieve during epitaxial growth. Hence, cyclic deposit and etch epitaxial growth in conjunction with a low temperature etching chemistry is desirable to achieve selectivity at temperatures lower than 625°C. In this paper, we apply the above concept to achieve selective growth of high strain SiGe (> 35%) at 500°C on test patterns corresponding to 65 nm node. SiGe is grown non-selectively first at 500°C with high order of silane as Si source, and Germane as Ge source followed by an etching chemistry also at 500°C to achieve selectivity. In addition, the growth rate of SiGe epitaxial film and the Ge concentration in the deposited epitaxial film were studied as a function of Si precursor flow; the effect of HCl introduction on Ge concentration and film growth rate was discussed. © 2011 Elsevier B.V. All rights reserved.