Electronic device using group III nitride semiconductor and its fabrication method and an epitaxial multi-layer wafer for making it
First Claim
1. A method of making a multi-layer wafer comprising(a) epitaxially depositing from vapor phase an active layer of Ga1-x2-y2Alx2Iny2N (0≦
- x2≦
1, 0≦
y2≦
1) at a first side of a substrate of Ga1-x1-y1Alx1Iny1N (0≦
x1≦
1, 0≦
y1≦
1) and epitaxially depositing-a transition layer, wherein the transition layer comprises Ga1-x3-y3Alx3Iny3N (0≦
x3≦
1, 0≦
y3≦
1) and wherein the transition layer resides between the first side of the substrate and the active layer,(b) wherein said substrate was formed by an ammonothermal method and said substrate has a second side opposite to the first side,(c) wherein the active layer and the transition layer are deposited to a combined thickness suitable to form an electronic device on the multi-layer wafer, said combined thickness being greater than a depth of a depletion region which is formed in the active layer after fabricating the electronic device with a first electrode on a top surface of the active layer and a second electrode on the second side of the substrate,(d) wherein the substrate has an oxygen concentration or an electron concentration greater than 1018 cm−
3 and(e) wherein said vapor phase has a sufficiently low concentration of oxygen or concentration of electrons to provide an oxygen concentration in the active layer of less than 1018 cm−
3.
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Accused Products
Abstract
The present invention discloses an electronic device using a group III nitride substrate fabricated via the ammonothermal method. By utilizing the high-electron concentration of ammonothermally grown substrates having the dislocation density less than 105 cm−2, combined with a high-purity active layer of Ga1-x-yAlxInyN (0≦x≦1, 0≦y≦1) grown by a vapor phase method, the device can attain high level of breakdown voltage as well as low on-resistance. To realize a good matching between the ammonothermally grown substrate and the high-purity active layer, a transition layer is optionally introduced. The active layer is thicker than a depletion region created by a device structure in the active layer.
22 Citations
18 Claims
-
1. A method of making a multi-layer wafer comprising
(a) epitaxially depositing from vapor phase an active layer of Ga1-x2-y2Alx2Iny2N (0≦ - x2≦
1, 0≦
y2≦
1) at a first side of a substrate of Ga1-x1-y1Alx1Iny1N (0≦
x1≦
1, 0≦
y1≦
1) and epitaxially depositing-a transition layer, wherein the transition layer comprises Ga1-x3-y3Alx3Iny3N (0≦
x3≦
1, 0≦
y3≦
1) and wherein the transition layer resides between the first side of the substrate and the active layer,(b) wherein said substrate was formed by an ammonothermal method and said substrate has a second side opposite to the first side, (c) wherein the active layer and the transition layer are deposited to a combined thickness suitable to form an electronic device on the multi-layer wafer, said combined thickness being greater than a depth of a depletion region which is formed in the active layer after fabricating the electronic device with a first electrode on a top surface of the active layer and a second electrode on the second side of the substrate, (d) wherein the substrate has an oxygen concentration or an electron concentration greater than 1018 cm−
3 and(e) wherein said vapor phase has a sufficiently low concentration of oxygen or concentration of electrons to provide an oxygen concentration in the active layer of less than 1018 cm−
3. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- x2≦
Specification