Method for selectively and epitaxially growing germanium in deep silicon groove

Abstract

The invention provides a method for selectively and epitaxially growing germanium in a deep silicon groove. The method comprises the following steps of: 1, depositing a hard mask on the surface of a silicon substrate, and manufacturing a deep silicon groove; 2, selectively and epitaxially growing germanium on the side wall and the bottom of the deep silicon groove at the same time; 3, performing high-temperature annealing to redistribute the germanium material on the side wall; 4, repeating the steps 2-3 to enable the epitaxial growth germanium surface at the deep silicon groove to be higher than the hard mask; 5, performing chemical mechanical polishing to enable the germanium surface to be flush with the surface of the hard mask; and 6, removing the hard mask, and completing selective epitaxial germanium of the deep silicon groove. According to the method provided by the invention, germanium / germanium-silicon epitaxy is carried out on the side wall and the bottom of the silicon groove at the same time, and the germanium / germanium-silicon epitaxy growth in the deep silicon groove can be realized under the condition that the morphology is not influenced by using a high-temperature germanium redistribution technology; and a silicon oxide layer does not need to be inserted between silicon and germanium, so that the coupling efficiency from a silicon waveguide to a germanium device is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for selectively epitaxial germanium in a deep silicon groove. Background technique [0002] The ability to selectively grow germanium on specific regions of a silicon substrate facilitates the integration of germanium-based optoelectronic devices with silicon-based high-speed optoelectronic integrated circuits. Potential applications include integrating high-performance germanium photodetectors, silicon optical modulators, and various silicon optical passive devices to form optical transceiver chips with high-speed transceiver functions. In addition to germanium detectors, both Ge and Ge / SiGe quantum wells (QW) exhibit electroabsorption effects (Franz effect), namely the Keldysh effect in Ge and the quantum confinement Stark effect (QCSE) in Ge / SiGe. An increase in the applied electric field redshifts the absorption spectrum, a behavior that allows the develop...

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Problems solved by technology

However, this method will insert a SiO2 barrier layer between the silicon waveguide and the germanium material, which will reduce the coupling efficiency of light.

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