Formation of germanium-containing channel region by thermal condensation utilizing an oxygen permeable material

摘要

A structure including a first semiconductor material portion and a second semiconductor material portion is provided. An oxygen impermeable hard mask is then formed directly on a surface of the first semiconductor material portion. Next, a silicon germanium layer is epitaxially formed on the second semiconductor material portion, but not the first semiconductor material portion. An oxygen permeable hard mask is then formed over the first and second semiconductor material portions. A thermal condensation process is then performed which converts the second semiconductor material portion into a germanium-containing semiconductor material portion. The oxygen permeable hard mask and the oxygen impermeable hard mask are then removed. A functional gate structure can be formed atop the remaining first semiconductor material portion and the thus formed germanium-containing semiconductor material portion.

主权项

1. A method of forming a semiconductor structure comprising:
providing a structure including a first semiconductor material portion and a second semiconductor material portion located on a surface of a substrate; forming an oxygen impermeable hard mask directly on a surface of said first semiconductor material portion, but not said second semiconductor material portion; epitaxially forming a silicon germanium layer directly contacting at least a topmost surface of said second semiconductor material portion; forming an oxygen permeable hard mask continuously over said first and second semiconductor material portions, wherein a first portion of said oxygen permeable hard mask is formed directly on exposed surfaces of said oxygen impermeable hard mask and a second portion of said oxygen permeable hard mask is formed directly on exposed surfaces of said silicon germanium layer; performing a thermal condensation process, wherein during said thermal condensation process oxygen diffuses through said oxygen permeable hard mask and said second semiconductor material portion is converted into a germanium-containing semiconductor material portion, and wherein said oxygen permeable hard mask prevents agglomeration of said first semiconductor material portion, said silicon germanium layer and said second semiconductor material portion during said thermal condensation process; and removing said oxygen permeable hard mask and said oxygen impermeable hard mask from said structure.