Selective epitaxial growth of stepwise SiGe:B at the recessed sources and drains: A growth kinetics and strain distribution study

Abstract

The selective epitaxial growth of Si1-xGex and the related strain properties were studied. Epitaxial Si1-xGex films were deposited on (100) and (110) orientation wafers and on patterned Si wafers with recessed source and drain structures via ultrahigh vacuum chemical vapor deposition using different growing steps and Ge concentrations. The stepwise process was split into more than 6 growing steps that ranged in thicknesses from a few to 120 nm in order to cover the wide stages of epitaxial growth. The growth rates of SiGe on the plane and patterned wafers were examined and a dependence on the surface orientation was identified. As the germanium concentration increased, defects were generated with thinner Si1-xGex growth. The defect generation was the result of the strain evolution which was examined for channel regions with a Si1-xGex source/drain (S/D) structure.

Lattice contraction with boron doping in fully strained SiGe epitaxial layers

“…The increased electron mobility and modulated band structure by the compressive stress of SiGe makes SiGe useful in applications such as raised source=drain as well as channel materials in conventional CMOS with improved device performance. [1][2][3] In order to apply SiGe layer to devices, it is usually doped with boron (B).…”

Atomistic Insights into Ultrafast SiGe Nanoprocessing

“…We point out that describing compound materials like SiGe and including the impact of off-lattice defects (like stacking faults and interstitial-like defects) during LA are the main improvements with respect to previously reported multiscale methods . In particular, we have described the theoretical background and computational implementation of the methodology in light of its application to the Si 1– x Ge x alloy, which represents one of the most promising candidates for 3D sequentially integrated devices, ,− spin-qubits, gate-all-around transistors, ,, or even direct-band-gap light emitters . The method was validated by comparing simulations for both relaxed and strained SiGe with the 1D phase-field results and experiments.…”

“…In this way, it not only overcomes the limits of purely continuum-based tools but also overcomes those of other hybrid FEM-KMC approaches, which either lack self-consistent information exchange between the two frameworks or are limited to defect-free LA simulations of silicon without any superlattice formulation . In particular, we demonstrate the method by focusing on ultraviolet nanosecond-pulsed-LA processes of SiGe, an alloy with composition-dependent electronic and optical properties − increasingly relevant to future nanoelectronic, ,,− thermoelectronic, optoelectronic, ,, and quantum technologies. ,− The multiscale methodology provides unique atomistic insights into the complex and ultrafast morphological, compositional, and structural transformations of SiGe during laser irradiation, ,,, giving invaluable support to process engineers aiming at the exploitation of this material’s full potential.…”

Heterodielectric oxide‐engineered single‐lateral pocket‐based gated source TFET

“…This is followed by an etch step for the subsequent growth of the low‐k SiO 2 by thermal oxidation. The SiO 2 from the top n+ pocket is then laterally etched, which is followed by the subsequent ultrahigh vacuum chemical vapor deposition of the p+ SiGe region 37 . This is followed by the growth of the high‐k HfO 2 through PVD 32 .…”