An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a p-type cap on the layers that form the heterostructure region, the p-type cap including an AIN layer and a p-type AlGaN or A l InGaN layer; a dielectric layer contacting the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the cap includes A ly GaN and A lx GaN, the A ly GaN is between the gate and the A lx GaN, and y>x.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the structure further comprises a layer of A l N between the first GaN material layer and the second GaN material layer.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the first GaN material layer is thicker in the access regions than in the gate region.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the second GaN material layer is doped n-type in the access regions but not in the gate region.

A high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; a p-type cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the p-type cap; and a gate on the p-type cap; wherein the first GaN material layer has an N-face adjacent to the cap, and wherein the dielectric layer includes an aperture and the p-type cap is in the aperture.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1, wherein the first GaN material layer has a Ga-face adjacent to the layer of A I GaN; a cap in a recess of an N-face of the first GaN material layer; a gate on the cap; and a source and drain on laterally opposing sides of the gate.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a p-type cap on the layers that form the heterostructure region, the p-type cap including an AIN layer and a p-type AlGaN or A l InGaN layer; a dielectric layer contacting the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the cap includes A ly GaN and A lx GaN, the A ly GaN is between the gate and the A lx GaN, and y>x.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the structure further comprises a layer of A l N between the first GaN material layer and the second GaN material layer.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the first GaN material layer is thicker in the access regions than in the gate region.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the second GaN material layer is doped n-type in the access regions but not in the gate region.

A high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; a p-type cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the p-type cap; and a gate on the p-type cap; wherein the first GaN material layer has an N-face adjacent to the cap, and wherein the dielectric layer includes an aperture and the p-type cap is in the aperture.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1, wherein the first GaN material layer has a Ga-face adjacent to the layer of A I GaN; a cap in a recess of an N-face of the first GaN material layer; a gate on the cap; and a source and drain on laterally opposing sides of the gate.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a p-type cap on the layers that form the heterostructure region, the p-type cap including an AIN layer and a p-type AlGaN or A l InGaN layer; a dielectric layer contacting the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the cap includes A ly GaN and A lx GaN, the A ly GaN is between the gate and the A lx GaN, and y>x.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the structure further comprises a layer of A l N between the first GaN material layer and the second GaN material layer.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the first GaN material layer is thicker in the access regions than in the gate region.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the second GaN material layer is doped n-type in the access regions but not in the gate region.

A high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; a p-type cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the p-type cap; and a gate on the p-type cap; wherein the first GaN material layer has an N-face adjacent to the cap, and wherein the dielectric layer includes an aperture and the p-type cap is in the aperture.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1, wherein the first GaN material layer has a Ga-face adjacent to the layer of A I GaN; a cap in a recess of an N-face of the first GaN material layer; a gate on the cap; and a source and drain on laterally opposing sides of the gate.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a p-type cap on the layers that form the heterostructure region, the p-type cap including an AIN layer and a p-type AlGaN or A l InGaN layer; a dielectric layer contacting the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a channel layer comprising a first GaN material and a tertiary or quate rn ary layer comprising a second GaN material, the second GaN material having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the cap includes A ly GaN and A lx GaN, the A ly GaN is between the gate and the A lx GaN, and y>x.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the structure further comprises a layer of A l N between the first GaN material layer and the second GaN material layer.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the first GaN material layer is thicker in the access regions than in the gate region.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; and a gate on the cap; wherein the device is an N-face enhancement mode high electron mobility transistor device, and wherein the device includes a gate region beneath the gate and access regions on either side of the gate region, and the second GaN material layer is doped n-type in the access regions but not in the gate region.

A high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1 or equal to 1; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the cap; a p-type cap on the layers that form the heterostructure region; a dielectric layer formed on the layers that form the heterostructure region and adjacent to the p-type cap; and a gate on the p-type cap; wherein the first GaN material layer has an N-face adjacent to the cap, and wherein the dielectric layer includes an aperture and the p-type cap is in the aperture.

An enhancement mode high electron mobility transistor device, comprising: a heterostructure region including a 2DEG therein, the heterostructure region comprising a first GaN material layer and a second GaN material layer, the second GaN material layer having an aluminum composition between 0 and 1, wherein the first GaN material layer has a Ga-face adjacent to the layer of A I GaN; a cap in a recess of an N-face of the first GaN material layer; a gate on the cap; and a source and drain on laterally opposing sides of the gate.