Method of producing nitride nanowires with different core and shell V/III flow ratios
View Patent ↗The present invention relates to the growing of nitride semiconductors, applicable for a multitude of semiconductor devices such as diodes, LEDs and transistors. According to the method of the invention nitride semiconductor nanowires are grown utilizing a CVD based selective area growth technique. A nitrogen source and a metal-organic source are present during the nanowire growth step and at least the nitrogen source flow rate is continuous during the nanowire growth step. The V/III-ratio utilized in the inventive method is significantly lower than the V/III-ratios commonly associated with the growth of nitride based semiconductor.
1. A method of growing nitride based semiconductor nanowires, comprising:
growing a plurality of Group III-nitride nanowires by chemical vapor deposition (CVD) in a nanowire growth step, wherein a nitrogen source flow and a metal-organic source flow are present;
forming at least one Group III-nitride shell layer on each of the plurality of Group III-nitride nanowires by CVD in a shell growth step, wherein the nitrogen source flow and the metal-organic source flow are present; and
forming a continuous Group III-nitride layer over the at least one Group III-nitride shell layer and continuously covering all of the plurality of Group III-nitride nanowires,
wherein:
a molar V/III-ratio comprises a molar ratio of the nitrogen source flow rate and the metal-organic source flow rate;
the molar V/III-ratio during the shell growth step is higher than the molar V/III-ratio during the nanowire growth step;
the at least one Group III-nitride shell layer comprises an active region of a light emitting diode (LED);
the plurality of Group III-nitride nanowires are doped one of n- or p-type; and
the continuous Group III-nitride layer is doped another one of p- or n-type to form a junction with the plurality of Group III-nitride nanowires.
2. The nanowire growth method of claim 1 , wherein forming the at least one Group III-nitride shell layer comprises a planar growth step.
3. The nanowire growth method of claim 2 , wherein the plurality of Group III-nitride nanowires comprise gallium nitride nanowires and the at least one Group III-nitride shell layer comprises an indium gallium nitride shell layer.
4. The nanowire growth method of claim 1 , wherein the molar V/III-ratio is in a range of 1-100 during the step of growing the plurality of Group III-nitride nanowires.
5. The nanowire growth method of claim 4 , wherein the molar V/III-ratio is in a range of 1-50 during the step of growing the plurality of Group III-nitride nanowires.
6. The nanowire growth method of claim 5 , wherein the molar V/III-ratio is in a range of 5-50 during the step of growing the plurality of Group III-nitride nanowires.
7. The nanowire growth method of claim 1 , wherein growing the plurality of Group III-nitride nanowires by CVD comprises utilizing a CVD based selective growth area technique.
8. The nanowire growth method of claim 7 , wherein the CVD based selective growth area technique comprises:
providing a substrate containing a growth mask;
forming openings in the growth mask; and
selectively growing the plurality of Group III-nitride nanowires in the openings of the growth mask.
9. The nanowire growth method of claim 1 , wherein a p-n junction is provided by each individual Group III-nitride nanowire combined with the continuous Group III-nitride layer.
10. A method of growing nitride based semiconductor nanowires, comprising:
growing a plurality of Group III-nitride nanowires by chemical vapor deposition (CVD) in a nanowire growth step, wherein a nitrogen source flow and a metal-organic source flow are present;
forming at least one Group III-nitride shell layer on each of the plurality of Group III-nitride nanowires by CVD in a shell growth step, wherein the nitrogen source flow and the metal-organic source flow are present; and
forming a continuous Group III-nitride layer over the at least one Group III-nitride shell layer and continuously covering all of the plurality of Group III-nitride nanowires,
wherein:
the at least one Group III-nitride shell layer comprises an active region of a light emitting diode (LED);
the plurality of Group III-nitride nanowires are doped one of n- or p-type; and
the continuous Group III-nitride layer is doped another one of p- or n-type to form a junction with the plurality of Group III-nitride nanowires.
11. The nanowire growth method of claim 10 , wherein growing the plurality of Group III-nitride nanowires by CVD comprises utilizing a CVD based selective growth area technique.
12. The nanowire growth method of claim 11 , wherein the CVD based selective growth area technique comprises:
providing a substrate containing a growth mask;
forming openings in the growth mask; and
selectively growing the plurality of Group III-nitride nanowires in the openings of the growth mask.
13. The nanowire growth method of claim 10 , wherein a p-n junction is provided by each individual Group III-nitride nanowire combined with the continuous Group III-nitride layer.