A method of forming a semiconductor structure for a III- N semiconductor channel device, the method comprising: forming a buffer structure on a Si-substrate, wherein forming said buffer structure comprises: forming a nucleation layer of AIN on the Si-substrate; forming a lower transition layer of (AI)GaN on the nucleation layer; forming a superlattice on said lower transition layer, said superlattice comprising at least one superlattice block, each superlattice block comprising a repetitive sequence of superlattice units, each superlattice unit comprising a plurality of layers, said plurality of layers comprising a first layer and a second layer formed on said first layer, wherein said first layer is a carbon-doped A IxGa₁-x N layer and said second layer is a carbon-doped Al yGa₁-y N layer, wherein x and y differ from each other, 0:x: 1 and 0<y< 1, wherein said first layer and second layer is epitaxially grown at a temperature of 980 0 C or lower and wherein the first layer and the second layer have a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm -3; and forming an upper transition layer of carbon-doped GaN on said superlattice, wherein the carbon-doped GaN has a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm⁻³; and forming a I II -N semiconductor channel layer on said upper transition layer of said buffer structure, wherein said channel layer is epitaxially grown at a temperature ranging from 1010 0 C to 1040 0 C and is grown to a thickness of 1 pm or smaller. Currently amended

(Cancel) Canceled

Canceled

Claims 9 and 10. Canceled

Canceled

(Cancel) Canceled

Canceled

A method of forming a semiconductor structure for a III- N semiconductor channel device, the method comprising: forming a buffer structure on a Si-substrate, wherein forming said buffer structure comprises: forming a nucleation layer of AIN on the Si-substrate; forming a lower transition layer of (AI)GaN on the nucleation layer; forming a superlattice on said lower transition layer, said superlattice comprising at least one superlattice block, each superlattice block comprising a repetitive sequence of superlattice units, each superlattice unit comprising a plurality of layers, said plurality of layers comprising a first layer and a second layer formed on said first layer, wherein said first layer is a carbon-doped A IxGa₁-x N layer and said second layer is a carbon-doped Al yGa₁-y N layer, wherein x and y differ from each other, 0:x: 1 and 0<y< 1, wherein said first layer and second layer is epitaxially grown at a temperature of 980 0 C or lower and wherein the first layer and the second layer have a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm -3; and forming an upper transition layer of carbon-doped GaN on said superlattice, wherein the carbon-doped GaN has a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm⁻³; and forming a I II -N semiconductor channel layer on said upper transition layer of said buffer structure, wherein said channel layer is epitaxially grown at a temperature ranging from 1010 0 C to 1040 0 C and is grown to a thickness of 1 pm or smaller. Currently amended

(Cancel) Canceled

Canceled

Claims 9 and 10. Canceled

Canceled

(Cancel) Canceled

Canceled

A method of forming a semiconductor structure for a III- N semiconductor channel device, the method comprising: forming a buffer structure on a Si-substrate, wherein forming said buffer structure comprises: forming a nucleation layer of AIN on the Si-substrate; forming a lower transition layer of (AI)GaN on the nucleation layer; forming a superlattice on said lower transition layer, said superlattice comprising at least one superlattice block, each superlattice block comprising a repetitive sequence of superlattice units, each superlattice unit comprising a plurality of layers, said plurality of layers comprising a first layer and a second layer formed on said first layer, wherein said first layer is a carbon-doped A IxGa₁-x N layer and said second layer is a carbon-doped Al yGa₁-y N layer, wherein x and y differ from each other, 0:x: 1 and 0<y< 1, wherein said first layer and second layer is epitaxially grown at a temperature of 980 0 C or lower and wherein the first layer and the second layer have a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm -3; and forming an upper transition layer of carbon-doped GaN on said superlattice, wherein the carbon-doped GaN has a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm⁻³; and forming a I II -N semiconductor channel layer on said upper transition layer of said buffer structure, wherein said channel layer is epitaxially grown at a temperature ranging from 1010 0 C to 1040 0 C and is grown to a thickness of 1 pm or smaller. Currently amended

(Cancel) Canceled

Canceled

Claims 9 and 10. Canceled

Canceled

(Cancel) Canceled

Canceled

A method of forming a semiconductor structure for a III- N semiconductor channel device, the method comprising: forming a buffer structure on a Si-substrate, wherein forming said buffer structure comprises: forming a nucleation layer of AIN on the Si-substrate; forming a lower transition layer of (AI)GaN on the nucleation layer; forming a superlattice on said lower transition layer, said superlattice comprising at least one superlattice block, each superlattice block comprising a repetitive sequence of superlattice units, each superlattice unit comprising a plurality of layers, said plurality of layers comprising a first layer and a second layer formed on said first layer, wherein said first layer is a carbon-doped A IxGa₁-x N layer and said second layer is a carbon-doped Al yGa₁-y N layer, wherein x and y differ from each other, 0:x: 1 and 0<y< 1, wherein said first layer and second layer is epitaxially grown at a temperature of 980 0 C or lower and wherein the first layer and the second layer have a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm -3; and forming an upper transition layer of carbon-doped GaN on said superlattice, wherein the carbon-doped GaN has a carbon-doping concentration ran ging from 10 19 cm⁻³ to 10 20 cm⁻³; and forming a I II -N semiconductor channel layer on said upper transition layer of said buffer structure, wherein said channel layer is epitaxially grown at a temperature ranging from 1010 0 C to 1040 0 C and is grown to a thickness of 1 pm or smaller. Currently amended

(Cancel) Canceled

Canceled

Claims 9 and 10. Canceled

Canceled

(Cancel) Canceled

Canceled