Abstract: A method for manufacturing a deep isolation trench (221) and a method for manufacturing a high-voltage LED chip. Steps of the method for manufacturing a deep isolation trench (221) are as follows: forming a mask layer (202) on a substrate (200), and forming, in the mask layer, through etching, multiple windows (204) isolated from each other, the bottom of each window exposing the substrate; with epitaxial lateral overgrowth, forming an epitaxial structure (212) inside each window and a part of the mask layer around the window, respectively, each epitaxial structure having a trapezoidal cross section with a long bottom and a short top, and a gap between adjacent epitaxial structures forming a first deep trench (214); etching each epitaxial structure, forming a first shoulder (218) and a second shoulder (221) at both sides of each epitaxial structure, respectively, and forming a deep isolation trench above the mask layer between the adjacent epitaxial structures.

Abstract: A method for manufacturing a deep isolation trench (221) and a method for manufacturing a high-voltage LED chip. Steps of the method for manufacturing a deep isolation trench (221) are as follows: forming a mask layer (202) on a substrate (200), and forming, in the mask layer, through etching, multiple windows (204) isolated from each other, the bottom of each window exposing the substrate; with epitaxial lateral overgrowth, forming an epitaxial structure (212) inside each window and a part of the mask layer around the window, respectively, each epitaxial structure having a trapezoidal cross section with a long bottom and a short top, and a gap between adjacent epitaxial structures forming a first deep trench (214); etching each epitaxial structure, forming a first shoulder (218) and a second shoulder (221) at both sides of each epitaxial structure, respectively, and forming a deep isolation trench above the mask layer between the adjacent epitaxial structures.