A semiconductor device comprising:na substrate;a carrier traveling layer formed on the substrate, made of first group III nitride semiconductor, and containing carriers traveling in a direction along a principal surface of the substrate;a barrier layer formed on the carrier traveling layer and made of second group III nitride semiconductor having a wider band gap than the first group III nitride semiconductor;an electrode formed on the barrier layer; anda cap layer formed on the barrier layer at a side of the electrode, and made of third group III nitride semiconductor containing a mixture of single crystals and polycrystals,wherein the single crystals takes over a crystal structure of the barrier layer.
›2.↳ 1The semiconductor device of claim 1, whereinnthe single crystals are disposed on an interface with the barrier layer.d2+3
The semiconductor device of claim 1, whereinnthe single crystals are disposed on an interface with the barrier layer.
›3.↳ 2The semiconductor device of claim 2, whereinnthe single crystals are formed non-uniformly in a thickness along the interface with the barrier layer.d3
The semiconductor device of claim 2, whereinnthe single crystals are formed non-uniformly in a thickness along the interface with the barrier layer.
›17.↳ 2The semiconductor device of claim 2, whereinnthe single crystals comprise a plurality of insular single crystal portions.d3+1
The semiconductor device of claim 2, whereinnthe single crystals comprise a plurality of insular single crystal portions.
›18.↳ 17The semiconductor device of claim 17, wherein the plurality of insular single crystal portions are covered by the polycrystals.d4
The semiconductor device of claim 17, wherein the plurality of insular single crystal portions are covered by the polycrystals.
›4.↳ 1The semiconductor device of claim 1, whereinnthe single crystals comprises a single crystal layer disposed on the interface with the barrier layer and…d2
The semiconductor device of claim 1, whereinnthe single crystals comprises a single crystal layer disposed on the interface with the barrier layer and an insular single crystal portion disposed on the single crystal layer.
›5.↳ 1The semiconductor device of claim 1, whereinnthe cap layer is made of group III nitride semiconductor containing aluminum (Al).d2+1
The semiconductor device of claim 1, whereinnthe cap layer is made of group III nitride semiconductor containing aluminum (Al).
›6.↳ 5The semiconductor device of claim 5, whereinna surface of the cap layer opposite to the substrate is oxidized.d3
The semiconductor device of claim 5, whereinna surface of the cap layer opposite to the substrate is oxidized.
›7.↳ 1The semiconductor device of claim 1, whereinnthe cap layer is made of aluminum nitride (AlN), the barrier layer is made of AlxGa1-xN, where 0<x≦1, a…d2
The semiconductor device of claim 1, whereinnthe cap layer is made of aluminum nitride (AlN), the barrier layer is made of AlxGa1-xN, where 0<x≦1, and the carrier traveling layer is made of GaN.
›8.↳ 1The semiconductor device of claim 1, further comprising:na spacer layer provided between the carrier traveling layer and the barrier layer, and made o…d2
The semiconductor device of claim 1, further comprising:na spacer layer provided between the carrier traveling layer and the barrier layer, and made of single crystal aluminum nitride (AlN).
›9.↳ 1The semiconductor device of claim 1, further comprising:na p-type group III nitride semiconductor layer provided between the barrier layer and the ele…d2+1
The semiconductor device of claim 1, further comprising:na p-type group III nitride semiconductor layer provided between the barrier layer and the electrode.
›10.↳ 9The semiconductor device of claim 9, whereinnthe p-type group III nitride semiconductor layer is made of AlxGa1-xN, wherein 0≦x≦1.d3
The semiconductor device of claim 9, whereinnthe p-type group III nitride semiconductor layer is made of AlxGa1-xN, wherein 0≦x≦1.
›11.↳ 1The semiconductor device of claim 1, further comprising:nan insulating layer provided between the barrier layer and the electrode.d2+1
The semiconductor device of claim 1, further comprising:nan insulating layer provided between the barrier layer and the electrode.
›12.↳ 11The semiconductor device of claim 11, whereinnthe insulating layer is made of aluminum oxide (Al2O3).d3
The semiconductor device of claim 11, whereinnthe insulating layer is made of aluminum oxide (Al2O3).
›13.↳ 1The semiconductor device of claim 1, whereinna portion of the barrier layer under the electrode has a smaller thickness than the side of the electrode…d2
The semiconductor device of claim 1, whereinna portion of the barrier layer under the electrode has a smaller thickness than the side of the electrode.
›14.↳ 1The semiconductor device of claim 1, whereinna sheet carrier concentration in the carrier traveling layer is more than 1×1013 cm−2.d2
The semiconductor device of claim 1, whereinna sheet carrier concentration in the carrier traveling layer is more than 1×1013 cm−2.
›15.↳ 1The semiconductor device of claim 1, wherein the single crystals have higher etching resistivity to an alkaline solution than the polycrystals.d2
The semiconductor device of claim 1, wherein the single crystals have higher etching resistivity to an alkaline solution than the polycrystals.
›16.↳ 1The semiconductor device of claim 1, wherein a crystalline size of the single crystals is greater than crystal sizes of the polycrystals.d2
The semiconductor device of claim 1, wherein a crystalline size of the single crystals is greater than crystal sizes of the polycrystals.
