SCHOTTKY BARRIER DIODE AND METHOD FOR MANUFACTURING THE SAME
A Schottky barrier diode (SBD) is provided, which improves electrical characteristics and optical characteristics by securing high crystallinity by including an n-gallium nitride (GaN) layer and a GaN layer which are doped with aluminum (Al). In addition, by providing a p-GaN layer on the Al-doped GaN layer, a depletion layer may be formed when a reverse current is applied, thereby reducing a leakage current. The SBD may be manufactured by etching a part of the Al-doped GaN layer and growing a p-GaN layer from the etched part of the Al-doped GaN layer. Therefore, a thin film crystal is not damaged, thereby increasing reliability. Also, since dedicated processes for ion implantation and thermal processing are not necessary, simplified process and reduced cost may be achieved.
1 . A Schottky barrier diode (SBD) comprising:
a substrate;
an n-gallium nitride (GaN) layer disposed on a surface of the substrate and doped with aluminum (Al);
a GaN layer disposed on the Al-doped n-GaN layer and doped with Al;
a first electrode disposed on the Al-doped GaN layer; and
a second electrode disposed on a surface of the substrate, opposite to the surface on which the Al-doped n-GaN layer is disposed.
2 . The SBD of claim 1 , further comprising a p-GaN layer disposed on the Al-doped GaN layer,
wherein the p-GaN layer is formed by growing on an etched part of the Al-doped GaN layer, and coming into contact with the first electrode.
3 . The SBD of claim 1 , wherein content of Al in the Al-doped n-GaN layer and the Al-doped GaN layer is in the range of 0.01% to 1%.
4 . The SBD of claim 1 , further comprising a buffer layer disposed on the substrate.
5 . The SBD of claim 1 , wherein the substrate comprises one selected from a group consisting of a silicon (Si) substrate, a silicon carbide (SiC) substrate, an aluminum nitride (AlN) substrate, and a gallium nitride (GaN) substrate.
6 . The SBD of claim 1 , wherein the first electrode comprises one selected from a group consisting of nickel (Ni), gold (Au), copper indium oxide (CuInO 2 ), indium tin oxide (ITO), platinum (Pt), and alloys thereof.
7 . The SBD of claim 1 , wherein the second electrode comprises one selected from a group consisting of chromium (Cr), Al, tantalum (Ta), thallium (Tl), and Au.
8 . A manufacturing method for a schottky barrier diode (SBD), comprising:
forming an aluminum (Al)-doped n-gallium nitride (GaN) layer on a surface of a substrate;
forming an Al-doped GaN layer on the Al-doped n-GaN layer;
forming a second electrode on a surface of the substrate, opposite to the surface on which the Al-doped n-GaN layer is disposed; and
forming a first electrode on the Al-doped GaN layer.
9 . The manufacturing method of claim 8 , further comprising forming a p-GaN layer disposed on the Al-doped GaN layer,
wherein the forming of the p-GaN layer comprises etching a part of the Al-doped GaN layer and growing the p-GaN layer from the etched part of the Al-doped GaN layer so that the grown p-GaN layer is brought into contact with the first electrode.
10 . The manufacturing method of claim 9 , wherein the forming of the p-GaN layer is performed in a temperature range of 1000° C. to 1200° C.
11 . The manufacturing method of claim 8 , wherein content of Al in the Al-doped n-GaN layer and the Al-doped GaN layer is in the range from 0.01% to 1%.
12 . The manufacturing method of claim 8 , wherein
the substrate is an insulating substrate, and
the forming of the second electrode is performed after removing the insulating substrate and forming a bonding layer to bond the Al-doped n-GaN layer to the second electrode.