FINFET STRUCTURES HAVING SILICON GERMANIUM AND SILICON FINS

摘要

A finned structure is fabricated using a bulk silicon substrate having a carbon doped epitaxial silicon layer. A pFET region of the structure includes silicon germanium fins. Such fins are formed by annealing the structure to mix a germanium containing layer with an adjoining crystalline silicon layer. The structure further includes an nFET region including silicon fins formed from the crystalline silicon layer. The germanium containing layer in the nFET region is removed to create a space beneath the crystalline silicon layer in the nFET region. An insulating material is provided within the space. The pFET and nFET regions are electrically isolated by a shallow trench isolation region.

主权项

1. A method comprising:
obtaining a structure comprising a bulk silicon substrate, an epitaxial layer comprising carbon doped silicon on the substrate, an epitaxial layer containing germanium on the carbon doped silicon layer, and a layer comprising crystalline silicon on the germanium containing layer; forming an isolation region on the structure electrically isolating a first region of the structure from a second region of the structure; removing the germanium containing layer from the second region of the structure, thereby forming a space within the second region beneath the crystalline silicon layer; forming an insulating layer within the space; thermally mixing the germanium containing layer and the crystalline silicon layer in the first region of the structure to form a layer comprising silicon germanium; forming a plurality of fins comprising silicon germanium in the first region from the silicon germanium layer, and forming a plurality of fins from the crystalline silicon layer in the second region.