A method for manufacturing a semiconductor device structure is provided. The method includes providing a base substrate and forming a buffer layer on the base substrate. The method also includes forming a patterned silicon layer on the buffer layer. The patterned silicon layer has an opening to expose a portion of the buffer layer. The method further includes epitaxially growing a patterned channel layer and a patterned barrier layer on a top surface of the patterned silicon layer sequentially. In addition, the method includes forming a gate electrode on the patterned barrier layer.