Case ID: M08-015P^

Published: 2020-02-26 11:13:33

Last Updated: 1677134830


John Kouvetakis
Yan-Yan Fang

Technology categories

Physical ScienceSemiconductors, Materials & Processes

Technology keywords


Licensing Contacts

Shen Yan
Director of Intellectual Property - PS
[email protected]

Selective Deposition of Ge-rich Si-Ge Layers from Single Source Si-Ge Hydrides

Employing selective epitaxy to grow fully strained Si-Ge
alloys in the source and drain (S/D) of a p-type metal-oxide semiconductor
(PMOS) transistor compresses the Si-channel to significantly increase the hole
mobility, and consequently, the speed of the device. Ge-rich alloys, where Ge
constitutes = 50% of the alloy, are of particular interest because of
expectations that these alloys will produce disruptive improvements in the
saturation/drive currents over traditional, Si-rich, configurations. Still,
current selective growth processes are unable to yield films with device quality
morphology and microstructure for the desired Ge range. Likewise, conventional
processes produce high dislocation densities, non-uniformities in strain, lack
of compositional control, and reduced film thickness in Ge-rich films, which
ultimately can degrade the quality and performance of the stressor material,
subsequently, limiting the practical usefulness of these approaches.

Researchers at Arizona State University have developed a
device quality method to selectively deposit Si-Ge materials, specifically
Ge-rich Si-Ge materials, on substrates. This method exploits the unexpected and
unique growth properties of Si-Ge hydride compounds to selectively deposit Si-Ge
layers, for example, as strained-layered heterostructures of Ge-rich
semiconductors in the S/D regions of PMOS structures. The method achieves high
strain states in Si-Ge layers that are typically much thicker than the nominal
equilibrium critical thickness during blanket growth.

Potential Applications

  • Semiconductors (e.g. CMOS, NMOS, PMOS, MOSFET, etc.)

    • Microelectronics

  • Optoelectronics (e.g. Photodiodes, etc.)

Benefits and Advantages

  • Provides Selective Area, Device Quality, Ge-Rich Si-Ge
    Alloys ? allows selective growth (renders high mobility devices and opens path
    to III-V integration with Si); produces monocrystalline microstructures,
    smooth and continuous surface morphologies, and low defect densities;
    demonstrates 50 ? 75% Ge content compared to the 20 ? 30% content of existing

  • Provides High Strain – up to 2.3 % demonstrated in
    blanket growth and typically much thicker than the nominal equilibrium
    critical thickness

  • Operates at CMOS-Compatible Low Temperatures ?
    heteroepitaxy at 300 – 450°C

  • Offers Simple Integration ? single source precursor
    eliminates the need for multi-component reactions and corrosive etching
    processes; high levels of controllability and uniformity