Method for making electronic device using group III nitride semiconductor having specified dislocation density oxygen/electron concentration, and active layer thickness

摘要

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.

主权项

1. A method of fabricating an electronic device comprising;
(a) growing an active layer of Ga1-x2-y2Alx2Iny2N (0≦x2≦1, 0≦y2≦1) by vapor phase epitaxy on a first side of a substrate of Ga1-x1-y1Alx1Iny1N (0≦x1≦1, 0≦y1≦1) sliced from a bulk crystal of Ga1-x1-y1Alx1Iny1N (0≦x1≦1, 0≦y1≦1) grown in supercritical ammonia; (b) forming an Ohmic contact on a second side of the substrate; (c) forming a Schottky contact, metal-insulator-semiconductor structure or p-type semiconductor on the active layer; wherein (d) the substrate has a dislocation density of less than 105 cm−2; (e) the substrate has electron concentration or an oxygen concentration higher than 1018 cm−3; (f) the active layer has an electron concentration or an oxygen concentration of Less than 1018 cm−3; (g) the active layer has a thickness greater than a thickness of the depletion region for any applied voltage within an operation range of the electronic device, and wherein the active layer has a concentration of sodium at least 100 times less than a concentration of sodium of the substrate, and the sodium concentration of the substrate is greater than 1016 cm−3.