Method for growing germanium-silicon epitaxial layers

Abstract

The invention provides a method for epitaxially growing SiGe epitaxial layers. The method is applied to filling the SiGe epitaxial layers in source and drain electrode regions of a PMOS (P-channel metal oxide semiconductor), and reaction gas containing Ge elements and carbonaceous gas are simultaneously filled into a reaction chamber, so that the carbonaceous SiGe epitaxial layers are selectively and epitaxially grown on surfaces of source and drain electrode regions of the surface of a silicon substrate. The method has the advantages that on the premise that contents of Ge elements in the SiGe epitaxial layers are guaranteed, critical thicknesses of the SiGe epitaxial layers are increased, strain relaxation is avoided, and the carrier mobility of the PMOS is improved.

Description

technical field [0001] The invention relates to a semiconductor manufacturing method, in particular to a silicon germanium epitaxial layer growth method. Background technique [0002] At present, the semiconductor manufacturing industry mainly grows devices on the wafer (wafer) device surface of the silicon substrate. For example, the metal-oxide semiconductor field effect transistor (Metal-Oxide Semiconductor Field Effect Transistor, MOSFET) device structure includes an active region, a source , a drain and a gate, wherein the active region is located in the semiconductor silicon substrate, the gate is located above the active region, and ion implantation is performed in the active regions on both sides of the gate to form a source and a drain There is a conductive channel under the gate, and there is a gate dielectric layer between the gate and the conductive channel. According to different types of ion implantation, hole type metal oxide semiconductor field effect transi...

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Problems solved by technology

[0020] In view of this, the technical problem solved by the present invention is: the increase of Ge content in the SiGe epitaxial layer above the PMOS source and drain regions will lead to relaxation of strain and rough surface morphology of the SiGe epitaxial layer, and the decrease of the critical thickness of the SiGe epitaxial layer

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