Carbon doping semiconductor devices
AssigneeTransphorm Inc.
InventorsStacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
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Abstract
A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm−3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm−2.
Claims6
A material structure, comprising:
- a first III-N semiconductor layer on a silicon substrate;
- and
- a second III-N semiconductor layer on a side of the first III-N semiconductor layer opposite the silicon substrate, the second III-N semiconductor layer being thinner than the first III-N semiconductor layer;
- wherein the first III-N semiconductor layer comprises an AlN nucleation layer directly on the silicon substrate and a III-N buffer layer disposed between the AlN nucleation layer and the second III-N semiconductor layer, such that the III-N buffer layer has a carbon concentration that is greater than 1×1018 cm−3 throughout the layer, and the carbon concentration of the III-N buffer layer is greater than the carbon concentration of the AlN nucleation layer;
- wherein a carbon concentration throughout the second III-N semiconductor layer is less than the carbon concentration throughout the III-N buffer layer;
- wherein a surface of the second III-N semiconductor layer that is opposite the silicon substrate has a density of macroscopic features which is less than 5 features/cm2, wherein each of the macroscopic features has an average height of greater than 100 nanometers;
- and wherein a dislocation density at a surface of the second III-N semiconductor layer opposite the silicon substrate is less than 2×109 cm−2.
Dependencies are inferred from the claim text.