Deep ultraviolet epitaxial wafer and preparation method thereof

[0028] The embodiment of the present invention provides a method for preparing a deep ultraviolet epitaxial wafer, comprising the steps of:

[0029] An aluminum nitride thin film buffer layer, a U-type aluminum gallium nitride layer, an N-type aluminum gallium nitride layer, a quantum well layer and a P-type gallium nitride layer are sequentially grown on the substrate, and the P-type gallium nitride includes sequentially grown P type aluminum gallium nitride layer, aluminum nitride layer, p-doped gallium nitride layer and heavily doped p-type aluminum gallium nitride layer.

[0030] It can be seen from the above description that the deep ultraviolet epitaxial wafer includes P-type GaN, and P-type GaN includes a P-type AlGaN layer, an AlN layer, a P-doped GaN layer, and a heavily doped P-type GaN layer. AlGaN layer. Among them, the P-type AlGaN layer can effectively reduce the absorption of deep ultraviolet light; on the basis of effectively reducing the absorption of deep ultra

[0045] Please refer to figure 1 , a deep ultraviolet epitaxial wafer, including an aluminum nitride film buffer layer, a U-type aluminum-gallium-nitride layer, an N-type aluminum-gallium-nitride layer, a quantum well layer and a P-type gallium nitride layer grown sequentially on a substrate.

[0046] P-type gallium nitride (GaN) includes a P-type aluminum gallium nitride (AlGaN) layer, an aluminum nitride (AlN) layer, a P-doped gallium nitride layer and a heavily doped P-type aluminum gallium nitride layer grown sequentially.

[0047] Specifically, the deep ultraviolet epitaxial wafer includes an AlN film buffer layer with a thickness of 15-20nm, a U-shaped AlGaN layer with a thickness of 1.5-2.5um, and a high Al composition AlGaN layer with a thickness of 25-35nm grown on the substrate in sequence. , an N-type AlGaN layer with a thickness of 1.5-2.5um, a stress release layer (gallium nitride) with a thickness of 70-90nm, an active region (quantum well layer) and a P-type GaN lay

[0051] A method for preparing a deep ultraviolet epitaxial wafer, comprising the steps of:

[0052] An aluminum nitride thin film buffer layer, a U-type aluminum gallium nitride layer, an N-type aluminum gallium nitride layer, a quantum well layer and a P-type gallium nitride layer are sequentially grown on the substrate, and the P-type gallium nitride includes sequentially grown P type aluminum gallium nitride layer, aluminum nitride layer, p-doped gallium nitride layer and heavily doped p-type aluminum gallium nitride layer.

[0053] Specifically, S1. Sputter an AlN thin film buffer layer with a thickness of 20 nm on the (0001) plane sapphire substrate layer (non-PSS) by means of magnetron sputtering.

[0054] S2, growing a 2um U-shaped AlGaN layer on the AlN film buffer layer.

[0055] S3, growing a 30nm-thick heavy Al component AlGaN layer and growing a 1.9um N-type AlGaN layer sequentially on the U-type AlGaN layer.

[0056] S4. An 80nm stress release layer (gallium nitrid