Group-III nitride based high electron mobility transistor (HEMT) with barrier/spacer layer
First Claim
1. A high electron mobility transistor (HEMT), comprising:
- a GaN buffer layer;
an AlyGa1−
yN (y>
0.5) layer on said GaN buffer layer;
an AlxGa1−
xN barrier layer on said AlyGa1−
yN layer opposite said GaN buffer layer, said AlyGa1−
yN layer having a higher Al content than said AlxGa1−
xN barrier layer; and
a 2DEG at the interface between said GaN buffer layer and said AlyGa1−
yN layer.
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Accused Products
Abstract
A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an AlyGa1−yN (y=1 or y 1) layer on the GaN buffer layer. An AlxGa1−xN (0≦x≦0.5) barrier layer on to the AlyGa1−yN layer, opposite the GaN buffer layer, AlyGa1−yN layer having a higher Al concentration than that of the AlxGa1−xN barrier layer. A preferred AlyGa1−yN layer has y=1 or y˜1 and a preferred AlxGa1−xN barrier layer has 0≦x≦0.5. A 2DEG forms at the interface between the GaN buffer layer and the AlyGa1−yN layer. Respective source, drain and gate contacts are formed on the AlxGa1−xN barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the AlyGa1−yN layer and a nucleation layer between the AlxGa1−xN buffer layer and the substrate.
280 Citations
34 Claims
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1. A high electron mobility transistor (HEMT), comprising:
-
a GaN buffer layer;
an AlyGa1−
yN (y>
0.5) layer on said GaN buffer layer;
an AlxGa1−
xN barrier layer on said AlyGa1−
yN layer opposite said GaN buffer layer, said AlyGa1−
yN layer having a higher Al content than said AlxGa1−
xN barrier layer; and
a 2DEG at the interface between said GaN buffer layer and said AlyGa1−
yN layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A group III nitride based high electron mobility transistor (HEMT), comprising:
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a semiconductor buffer layer;
a high polarization semiconductor layer on said buffer layer;
a semiconductor barrier layer on said high polarization layer so that said high polarization layer is sandwiched between said buffer and barrier layers, each of said layers having a non-zero total polarization pointing in the same direction, the magnitude of said polarization in said high polarization layer higher than the polarization of said buffer and barrier layers; and
a two dimensional electron gas at the interface between said buffer layer and said high polarization layer. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A high electron mobility transistor (HEMT), comprising:
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a bottom layer of Group III nitride semiconductor material;
a middle layer of Group III nitride semiconductor material on said bottom layer, wherein said middle layer can comprise one or more Group III elements one of which is Al;
a top layer of Group III nitride semiconductor material on said middle layer, opposite said bottom layer, wherein said top layer can comprise one or more Group III elements, said middle layer having Al concentration that is higher than 50% and said Al in said middle layer also having a concentration that is higher than the concentration of any Al in said top layer; and
a 2DEG at the interface between said middle and bottom layer. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification