Development of Light Emitting Group IV Ternary Alloys on Si Platforms for Long Wavelength Optoelectronic Applications

Abstract

This paper describes preparation of a new class of Ge1–x–ySixSny direct-gap semiconductors grown on Ge-buffered Si substrates via depositions of trigermane (Ge3H8), tetragermane (Ge4H0), tetrasilane (Si4H10), and stannane (SnD4) hydride precursors. These react at ultralow temperatures 320–290 °C to produce thick (∼500 nm) monocrystalline films with concentrations closely reflecting the gas phase molar ratio of the coreactants. A series of Ge-rich samples with a fixed 3–4% Si content and progressively increasing Sn content in the 4–10% range are grown to explore the possibility of obtaining direct gap materials for the first time in this semiconductor system. The resultant films also exhibit residual compressive strains that are largely relaxed via rapid thermal annealing between 550 and 700 °C depending on composition. These temperatures are 50–75 °C above the thermal decomposition threshold of Ge1–ySny/Ge materials with same Sn content, indicating that the ternaries are significantly more robust than the...