Formation of common interfacial layer on Si/SiGe dual channel complementary metal oxide semiconductor device
A method is presented for forming a semiconductor structure. The method includes forming a silicon (Si) channel for a first device, forming a first interfacial layer over the Si channel, forming a silicon-germanium (SiGe) channel for a second device, forming a second interfacial layer over the SiGe channel, and selectively removing germanium oxide (GeO X ) from the second interfacial layer by applying a combination of hydrogen (H 2 ) and hydrogen chloride (HCl). The second interfacial is silicon germanium oxide (SiGeO X ) and removal of the GeO X results in formation of a pure silicon dioxide (SiO 2 ) layer.
1. A semiconductor structure comprising:
a first channel formed for a first device;
a first interfacial layer disposed over the first channel;
a second channel formed for a second device; and
a second interfacial layer disposed over the second channel;
wherein germanium oxide (GeO X ) is selectively removed from the second interfacial layer by applying a combination of gases to convert the first interfacial layer to have a same chemical compound as the second interfacial layer and a high-k metal gate is then disposed in direct contact with the converted first interfacial layer.
2. The structure of claim 1 , wherein the first device is an n-type field effect transistor (nFET).
3. The structure of claim 1 , wherein the second device is a p-type field effect transistor (pFET).
4. The structure of claim 1 , wherein the first channel is silicon (Si), the second channel is silicon germanium (SiGe), and the second interfacial is silicon germanium oxide (SiGeO X ).
5. The structure of claim 1 , wherein removal of the GeO X results in formation of a pure silicon dioxide (SiO 2 ) layer.
6. The structure of claim 1 , wherein the converted first interfacial layer is formed between spacers.
7. The structure of claim 6 , wherein the combination of gases are applied to sidewalls of the spacers before the converted first interfacial layer is formed.
8. The structure of claim 1 , wherein removal of the GeO X prevents breaking of Si—O bonds in the second interfacial layer.
9. The structure of claim 1 , wherein removal of the GeO X results in decreased interface trap density in the second interfacial and the second channel.
10. The structure of claim 1 , wherein the gases are a combination of hydrogen (H 2 ) and hydrogen chloride (HCl).
11. A semiconductor structure comprising:
a first channel formed for a first device;
a first interfacial layer disposed in direct contact with the first channel;
a second channel formed for a second device; and
a second interfacial layer disposed in direct contact with the second channel, the second interfacial layer constructed from a different material than the first interfacial layer;
wherein germanium oxide (GeO X ) is selectively removed from the second interfacial layer by applying a combination of gases to convert the first interfacial layer to have a same chemical compound as the second interfacial layer.
12. The structure of claim 11 , wherein a high-k metal gate is disposed in direct contact with the converted first interfacial layer.
13. The structure of claim 11 , wherein the first channel is silicon (Si), the second channel is silicon germanium (SiGe), and the second interfacial is silicon germanium oxide (SiGeO X ).
14. The structure of claim 11 , wherein removal of the GeO X results in formation of a pure silicon dioxide (SiO 2 ) layer.
15. The structure of claim 11 , wherein the converted first interfacial layer is formed between spacers.
16. The structure of claim 11 , wherein the combination of gases are applied to sidewalls of the spacers before the converted first interfacial layer is formed.
17. The structure of claim 11 , wherein removal of the GeO X prevents breaking of Si—O bonds in the second interfacial layer.
18. The structure of claim 11 , wherein removal of the GeO X results in decreased interface trap density in the second interfacial and the second channel.
19. The structure of claim 11 , wherein the gases are a combination of hydrogen (H 2 ) and hydrogen chloride (HCl).
20. The structure of claim 11 , wherein the first device is an n-type field effect transistor (nFET) and the second device is a p-type field effect transistor (pFET).