Semiconductor substrate with multiple SiGe regions having different germanium concentrations by a single epitaxy process

摘要

A substrate with two SiGe regions having different Germanium concentrations and a method for making the same. The method includes: providing a substrate with at least two active regions; epitaxially depositing a first SiGe layer over each active regions; epitaxially depositing a Silicon layer over each SiGe layer; epitaxially depositing a second SiGe layer over each Silicon layer; forming a hard mask over the second SiGe layer of one of the active regions; removing the epitaxially deposited second SiGe layer of the unmasked active region, removing the hard mask, and thermally mixing the remaining Silicon and SiGe layers of the active regions to form a new SiGe layer with uniform Germanium concentration for each of the active regions, where the new SiGe layer with uniform Germanium concentration of one of the at least two active regions has a different concentration of Germanium than the new SiGe layer with uniform Germanium concentration of the other SiGe layer.

主权项

1. A method comprising:
providing an extremely-thin-semiconductor-on-insulator (ETSOI) substrate with at least two active regions, the ETSOI substrate having a semiconductor material layer having a thickness between 1 nm and 10 nm; depositing a first SiGe layer over each of the at least two active regions; depositing a Si layer over each of the SiGe layers; depositing a second SiGe layer over each of the Si layers; depositing a hard mask over one of the at least two active regions, a other of the at least two active regions is not covered by the deposited hard mask; removing the deposited second SiGe layer associated with the other of the at least two active regions; removing the deposited hard mask; and thermally mixing remaining Si and SiGe layers of the at least two active regions to form a new SiGe layer with a first uniform Germanium concentration for one of the at least two active regions, another new SiGe layer with a second uniform Germanium concentration for another one of the at least two active regions, wherein the first uniform Germanium concentration is different from the second uniform Germanium concentration.