In one general embodiment, a process includes a repeated sequence of growing a first layer having a first type of electrically active dopant and growing a second layer having a second type of electrically active dopant, where the first type of electrically active dopant of the first layer is one of either a P-type or an N-type and the second type of electrically active dopant of the second layer is the other one of either the P-type or N-type.

Disclosed are a Schottky diode and a manufacturing method thereof. The Schottky diode includes a substrate, a first semiconductor layer, a heterostructure layer, a passivation layer, and a cap layer stacked in sequence. The passivation layer includes a first groove and a second groove, and the first groove and the second groove penetrate through at least the passivation layer. A first electrode is arranged at least on the cap layer corresponding to the first groove; a second electrode is arranged in the second groove. A Schottky contact is formed between the first electrode and the cap layers, so that a direct contact area between the first electrode and the heterostructure layer may be avoided, a contradiction between the forward turn-on voltage and the reverse leakage of the Schottky diode may be balanced, and a leakage characteristic of the heterostructure layer in a high temperature environment may be suppressed.

A diode structure is described. In one example, a diode structure includes an N-type layer of gallium arsenide (GaAs) semiconductor material comprising a first dopant, an intrinsic layer of GaAs semiconductor material formed on the N-type layer, and a P-type layer of GaAs semiconductor material comprising a second dopant and being formed on the intrinsic layer. A top surface perimeter of the P-type layer includes a width W and a length L. An aspect ratio of the P-type layer is defined as a ratio of W and L, and W is greater than L or L is greater than W such that the aspect ratio of the P-type layer is 2 or greater. In other aspects, the top surface perimeter of the of the P-type layer includes a first straight portion, a first semi-ring-shaped portion, a second semi-ring-shaped portion, and a second straight portion.

This diode has an undoped GaN layer 11, an Al.sub.xGa.sub.1-xN layer (0<x<1) 12 thereon, a Mg-doped p-type In.sub.yGa.sub.1-yN layer (0<y<1) 13 having an island-like shape thereon, a metal electrode 14 thereon, an anode electrode 15 which is provided on the Al.sub.xGa.sub.1-xN layer 12 and which is electrically connected to the metal electrode 14 and a cathode electrode 16 which is provided on a part of the Al.sub.xGa.sub.1-xN layer 12 which is located on the opposite side from the anode electrode 15 with respect to the p-type In.sub.yGa.sub.1-yN layer 13. In this diode, at a non-operating time, a two-dimensional electron gas 17 is formed in the undoped GaN layer 11 in the vicinity part of a hetero-interface between the Al.sub.xGa.sub.1-xN layer 12 and the undoped GaN layer 11 except a part below the p-type In.sub.yGa.sub.1-yN layer 13.