Unconventional Growth Mechanism for Monolithic Integration of III–V on Silicon

Abstract

The heterogeneous integration of III-V optoelectronic devices with Si electronic circuits is highly desirable because it will enable many otherwise unattainable capabilities. However, direct growth of III-V thin film on silicon substrates has been very challenging because of large mismatches in lattice constants and thermal coefficients. Furthermore, the high epitaxial growth temperature is detrimental to transistor performance. Here, we present a detailed studies on a novel growth mode which yields a catalyst-free (Al,In)GaAs nanopillar laser on a silicon substrate by metal-organic chemical vapor deposition at the low temperature of 400 °C. We study the growth and misfit stress relaxation mechanism by cutting through the center of the InGaAs/GaAs nanopillars using focused ion beam and inspecting with high-resolution transmission electron microscopy. The bulk material of the nanopillar is in pure wurtzite crystal phase, despite the 6% lattice mismatch with the substrate, with all stacking disorders well confined in the bottom-most transition region and terminated horizontally. Furthermore, InGaAs was found to be in direct contact with silicon, in agreement with the observed crystal orientation alignment and good electrical conduction across the interface. This is in sharp contrast to many III-V nanowires on silicon which are observed to stem from thin SiN(x), SiO(2), or SiO(2)/Si openings. In addition, GaAs was found to grow perfectly as a shell layer on In(0.2)Ga(0.8)As with an extraordinary thickness, which is 15 times greater than the theoretical thin-film critical thickness for a 1.5% lattice mismatch. This is attributed to the core-shell radial geometry allowing the outer layers to expand and release the strain due to lattice mismatch. The findings in this study redefine the rules for lattice-mismatched growth on heterogeneous substrates and device structure design.

Single Crystalline InGaAs Nanopillar Grown on Polysilicon with Dimensions beyond the Substrate Grain Size Limit

“…Details of sample preparation can be found in our previous work. 12 More than ten nanopillars growing along different directions were examined in this work to obtain a general qualification of crystalline quality. Surrounding the nanopillar, InGaAs evolves into polycrystalline thin film.…”

Nanophotonic integrated circuits from nanoresonators grown on silicon

“…With tiny footprints, nanostructures incur minimal real estate cost while offering full photonic functionality. Furthermore, optoelectronic devices in PICs require a diverse set of materials, and nanostructure growth has proven promising for heterogeneous material integration 13,14 .…”

“…Recently, we showed that this is possible via growth of InGaAs nanopillars on silicon. Though they first nucleate as nanoneedles only a few nanometres wide 24,25 , they can scale well beyond 1 mm in diameter while remaining single crystalline 13,26 . Exhibiting strong optical cavity effects, these structures are natural nanoresonators 27 .…”

Дисперсия Масштабно-Инвариантных Функций Распределения По Размерам

“…Поэтому даль-нейшие результаты будут формулироваться для гетерогенной схемы роста (5) и в терминологии ННК. Отметим, однако, что схема (5) может представлять интерес и для других нанообъектов, например, самоиндуцированных квантовых точек и наноигл на рассогласованных подложках [16,17].…”