Method for forming a semiconductor device and structure thereof
View Patent ↗A non-planar semiconductor device ( 10 ) starts with a silicon fin ( 42 ). A source of germanium (e.g. 24, 26, 28, 30, 32 ) is provided to the fin ( 42 ). Some embodiments may use deposition to provide germanium; some embodiments may use ion implantation ( 30 ) to provide germanium; other methods may also be used to provide germanium. The fin ( 42 ) is then oxidized to form a silicon germanium channel region in the fin ( 36 ). In some embodiments, the entire fin ( 42 ) is transformed from silicon to silicon germanium. One or more fins ( 36 ) may be used to form a non-planar semiconductor device, such as, for example, a FINFET, MIGFET, Tri-gate transistor, or multi-gate transistor.
1. A method for forming a non-planar semiconductor device, comprising:
forming a fin, a first current electrode, and a second current electrode of the non-planar semiconductor device, wherein the fin, the first current electrode, and the second current electrode each comprises silicon;
providing a source of germanium to the fin, to the first current electrode, and to the second current electrode,
wherein providing the source of germanium to the fin comprises implanting the fin with germanium;
oxidizing to distribute the germanium throughout the fin, to form an inner region and an outer region of the first current electrode, and to form an inner region and an outer region of the second current electrode, wherein the outer region of the first electrode comprises germanium but the inner region of the first electrode does not comprise germanium, and wherein the outer region of the second current electrode comprises germanium but the inner region of the second electrode does not comprise germanium; and
completing formation of the non-planar semiconductor device.
2. A method as in claim 1 , wherein implanting the fin with germanium comprises using an implant angle in a range of 30 degrees to 10 degrees.
3. A method as in claim 1 , wherein said step of implanting the fin with germanium comprises:
using a germanium atom dose in a range of 5×10e13 to 5×10e16.
4. A method as in claim 1 , wherein said step of implanting the fin with germanium comprises:
using an ion implant energy in a range of 1 keV to 120 keV.
5. A method as in claim 1 , wherein said step of providing the source of germanium to the fin comprises:
forming a silicon germanium layer on the sidewalls of the fin.
6. A method as in claim 1 , wherein an insulating layer overlies at least a portion of the fin.
7. A method as in claim 1 , wherein the non-planar semiconductor device is formed using a wafer portion comprising a first insulating layer overlying a substrate, a monocrystalline semiconductor layer overlying the first insulating layer, and a second insulating layer overlying the monocrystalline semiconductor layer.
8. A method as in claim 1 , further comprising:
after said step of forming the fin and before said step of providing the source of germanium, forming a silicon nitride layer overlying the fin.
9. A method as in claim 1 , further comprising:
after said step of oxidizing the fin, etching at least a portion of silicon dioxide formed during the oxidation step.
10. A method as in claim 1 , wherein the channel region comprises all of the fin.
11. A method as in claim 1 , wherein the non-planar semiconductor device comprises a FINFET.
12. A method as in claim 1 , wherein the non-planar semiconductor device comprises a MIGFET.
13. A method as in claim 1 , wherein the non-planar semiconductor device comprises a Tri-gate transistor.
14. A method for forming a non-planar semiconductor device, comprising:
forming a fin, a first current electrode, and a second current electrode of the non-planar semiconductor device, wherein the fin, the first current electrode, and the second current electrode each comprises silicon;
providing a source of germanium to the fin, to the first current electrode, and to the second current electrode;
oxidizing to distribute the germanium throughout the fin, to form an inner region and an outer region of the first current electrode, and to form an inner region and an outer region of the second current electrode, wherein the outer region of the first electrode comprises germanium but the inner region of the first electrode does not comprise germanium, and wherein the outer region of the second current electrode comprises germanium but the inner region of the second electrode does not comprise germanium; and
completing formation of the non-planar semiconductor device.
15. A method as in claim 14 , further comprising:
removing at least a portion of an oxide formed during said step of oxidizing.
16. A method as in claim 14 , wherein the non-planar semiconductor device comprises a FINFET.
17. A method as in claim 14 , wherein the non-planar semiconductor device comprises a MIGFET.
18. A method for forming a non-planar semiconductor device, comprising:
forming a fin, a first current electrode, and a second current electrode of the non-planar semiconductor device, wherein the fin, the first current electrode, and the second current electrode each comprises silicon;
providing a source of germanium to the fin, to the first current electrode, and to the second current electrode;
oxidizing to distribute the germanium throughout the fin, to form an inner region and an outer region of the first current electrode, and to form an inner region and an outer region of the second current electrode, wherein the outer region of the first electrode comprises germanium but the inner region of the first electrode does not comprise germanium, and wherein the outer region of the second current electrode comprises germanium but the inner region of the second electrode does not comprise germanium; and
completing formation of the non-planar semiconductor device,
wherein the non-planar semiconductor device is formed using a wafer portion comprising a first insulating layer overlying a substrate, a monocrystalline semiconductor layer overlying the first insulating layer, and a second insulating layer overlying the monocrystalline semiconductor layer.
19. A method as in claim 18 , wherein said step of providing the source of germanium to the fin comprises forming a silicon germanium layer on the sidewalls of the fin, and wherein said step of forming the silicon germanium layer on the sidewalls of the fin comprises deposition of silicon germanium.
20. A method as in claim 19 , wherein the deposition of silicon germanium is selective.