The application provides an epitaxial method of a
germanium material layer, which comprises the following steps: forming a first insulating layer on the surface of a substrate;
etching the first insulating layer to form a window, and a part of the surface of the substrate is exposed from the window; and placing the substrate with the window into a reaction cavity, introducing a process gas and a carrier gas into the reaction cavity, controlling the pressure and the epitaxial temperature of the reaction cavity, and epitaxially growing a
germanium material layer on the surface of the substrate in the window, wherein the flow rate of the process gas is 10-300 standard cubic centimeters per minute (sccm), and the epitaxial temperature is 450-650 degrees Celsius. The epitaxial method of the
germanium material layer is carried out through suitable
process conditions, which can avoid the lateral outgrowth of the germanium material out of the window and the edge protrusion of the germanium material, so as to improve the quality of the germanium material layer, and further meet the requirements of subsequent processes and devices.