Method of tuning doping concentration in III-V compound semiconductor through co-doping donor and acceptor impurities
A method includes epitaxially growing a first III-V compound semiconductor, wherein the first III-V compound semiconductor is of p-type. The first III-V compound semiconductor is grown using precursors including a first precursor comprising Cp2Mg, and a second precursor comprising a donor impurity. A second III-V compound semiconductor is grown overlying and contacting the first III-V compound semiconductor. The second III-V compound semiconductor is of n-type.
1. A method comprising:
epitaxially growing a first III-V compound semiconductor, wherein the first III-V compound semiconductor is of p-type, and is grown by simultaneously using precursors comprising:
first precursors comprising a group III element and a group V element;
a second precursor comprising bis cyclopentadienyl magnesium (Cp2Mg); and
a third precursor comprising a donor impurity selected from germanium, tin, selenium, and tellurium.
2. The method of claim 1 , wherein the third precursor comprises silicon, germanium, tin, selenium, or tellurium.
3. The method of claim 1 further comprising;
epitaxially growing a second III-V compound semiconductor overlying and contacting the first III-V compound semiconductor, wherein the second III-V compound semiconductor is of n-type;
forming a gate dielectric over the second III-V compound semiconductor;
forming a gate electrode over the gate dielectric; and
forming a source region and a drain region connected to opposite ends of the second IIIV compound semiconductor, wherein the source region and the drain region are of n-type.
4. The method of claim 3 further comprising:
forming Shallow Trench Isolation (STI) regions in a semiconductor substrate;
removing a portion of the semiconductor substrate between two opposite portions of the STI regions to form a recess, wherein the first III-V compound semiconductor is grown in the recess; and
recessing the STI regions, wherein a portion of the first III-V compound semiconductor over the STI regions forms a fin, and wherein the second III-V compound semiconductor is grown on the fin.
5. A method comprising:
epitaxially growing a first In-V compound semiconductor, wherein during the growing the first In-V compound semiconductor, magnesium and a donor impurity are in-situ codoped;
epitaxially growing a second In-V compound semiconductor overlying and contacting the first In-V compound semiconductor, wherein during the growing the second In-V compound semiconductor, neither the magnesium nor the donor impurity is doped;
forming a gate dielectric over the second In-V compound semiconductor;
forming a gate electrode over the gate dielectric; and
forming a source region and a drain region on opposite ends of the second In-V compound semiconductor, wherein the source region and the drain region are of n-type.
6. The method of claim 5 , wherein the first In-V compound semiconductor is of p-type, and the second In-V compound semiconductor is of n-type.
7. The method of claim 5 , wherein the first In-V compound semiconductor is selected from the group consisting essentially of InP, InAlAs, and combinations thereof, and wherein the second In-V compound semiconductor comprises InGaAs.
8. The method of claim 5 , wherein the first In-V compound semiconductor has a p-type carrier concentration lower than about 1E17 /cm 3 .
9. The method of claim 5 further comprising:
forming Shallow Trench Isolation (STI) regions in a semiconductor substrate;
removing a portion of the semiconductor substrate between two opposite portions of the STI regions to form a recess, wherein the first In-V compound semiconductor is grown in the recess; and
recessing the STI regions, wherein a portion of the first In-V compound semiconductor over the STI regions form a fin, and wherein the second In-V compound semiconductor is grown on the fin.
10. The method of claim 5 , wherein the donor impurity comprises silicon, and wherein in the epitaxially growing the second In-V compound semiconductor, the silicon is supplied through a precursor comprising SiH 4 or Si 2 H 6 .
11. The method of claim 5 , wherein the donor impurity comprises germanium, and wherein in the epitaxially growing the second In-V compound semiconductor, silicon is supplied through a precursor comprising GeH 4 or Ge 2 H 6 .
12. The method of claim 5 further comprising:
forming Shallow Trench Isolation (STI) regions in a semiconductor substrate;
removing a portion of the semiconductor substrate between two opposite portions of the STI regions to form a recess, wherein the first In-V compound semiconductor is grown in the recess; and
recessing the STI regions, wherein a portion of the first In-V compound semiconductor over the STI regions forms a fin, and wherein the second In-V compound semiconductor is grown on the fin.
13. The method of claim 5 , wherein the donor impurity comprises germanium, tin, selenium, or tellurium.
14. A method comprising:
epitaxially growing a first III-V compound semiconductor, wherein the first III-V compound semiconductor is of p-type, and wherein the epitaxially growing the first III-V compound semiconductor is performed using precursors comprising:
a first precursor comprising bis cyclopentadienyl magnesium (Cp2Mg); and
a second precursor comprising a donor impurity;
epitaxially growing a second III-V compound semiconductor overlying and contacting the first III-V compound semiconductor, wherein the second III-V compound semiconductor is of n-type;
forming a gate dielectric over the second III-V compound semiconductor;
forming a gate electrode over the gate dielectric; and
forming a source region and a drain region connected to opposite ends of the second IIIV compound semiconductor, wherein the source region and the drain region are of n-type.
15. The method of claim 14 , wherein during the epitaxially growing the second III-V compound semiconductor, no donor impurity that turns the second III-V compound semiconductor toward n-type is used.
16. The method of claim 14 , wherein during the epitaxially growing the second III-V compound semiconductor, no Cp2Mg is used.
17. The method of claim 14 further comprising:
forming Shallow Trench Isolation (STI) regions in a semiconductor substrate;
removing a portion of the semiconductor substrate between two opposite portions of the STI regions to form a recess, wherein the first III-V compound semiconductor is grown in the recess; and
recessing the STI regions, wherein a portion of the first III-V compound semiconductor over the STI regions forms a fin, and wherein the second III-V compound semiconductor is grown on the fin.
18. The method of claim 14 , wherein the donor impurity comprises silicon, and wherein the second precursor is selected from the group consisting essentially of SiH 4 , Si 2 H 6 , GeH 4 , Ge 2 H 6 , and combinations thereof.
19. The method of claim 14 , wherein the epitaxially growing the first III-V compound semiconductor and the epitaxially growing the second III-V compound semiconductor comprise Metal-Organic Chemical Vapor Deposition (MOCVD).
20. The method of claim 14 , wherein the donor impurity comprises germanium, tin, selenium, or tellurium.