Synthesis of ternary SiGeSn semiconductors on Si(100) via SnxGe1−x buffer layers

Abstract

Single-phase Si1−x−yGexSny alloys with random diamond cubic structures are created on Si(100) via ultrahigh vacuum chemical vapor deposition reactions of SnD4 with SiH3GeH3 at 350 °C. Commensurate heteroepitaxy is facilitated by Ge1−xSnx buffer layers, which act as templates that can conform structurally and absorb the differential strain imposed by the more rigid Si and Si–Ge–Sn materials. The crystal structure, elemental distribution and morphological properties of the Si1−x−yGexSny/Ge1−xSnx heterostructures are characterized by high-resolution electron microscopy, including electron energy loss nanospectroscopy, x-ray diffraction (rocking curves) and atomic force microscopy. These techniques demonstrate growth of perfectly epitaxial, uniform and highly aligned layers with atomically smooth surfaces and monocrystalline structures that have lattice constants close to that of Ge. Rutherford backscattering ion channeling shows that the constituent elements occupy random substitutional sites in the same average diamond cubic lattice and the Raman shifts are consistent with the lattice expansion produced by the Sn incorporation into SiGe tetrahedral sites.

Growth and applications of GeSn-related group-IV semiconductor materials

“…Kouvetakis's group proposed using SnD 4 as a precursor because SnD 4 is more stable than SnH 4 , which has autoproteolysis characteristics. They reported the epitaxial growth of unstrained Ge 1−x Sn x layers with an Sn content from 2 to 15% on Si(001) substrates using the low-pressure CVD method at 250-350°C with a combination of the precursors SnD 4 and Ge 2 H 6 [44][45][46]. They also reported CVD growth with the combination of Ge 3 H 8 and SnD 4 precursors for lowering the growth temperature of Ge 1−x Sn x layers [11].…”

Strain-free Ge∕GeSiSn quantum cascade lasers based on L-valley intersubband transitions

“…Ge 1−x−y Si x Sn y alloys have been studied for the possibility of forming direct band gap semiconductors. [6][7][8][9] Since the initial growth of this alloy, 10 device-quality epilayers with a wide range of alloy contents have been achieved. Incorporation of Sn provides the opportunity to engineer separately the strain and band structure since we can vary the Si ͑x͒ and Sn ͑y͒ compositions independently.…”

Tensely strained GeSn alloys as optical gain media

“…12 However, high quality GeSn layers were only recently achieved in production tools. 10,13,14 Our growth studies were performed in an industrycompatible Reduced Pressure Chemical Vapor Deposition (RP-CVD) AIXTRON TRICENT® reactor with a showerhead which provides a highly uniform gas precursor distribution over 200 mm wafers.…”