Patent ID: 11876093
Assignee: RICHTEK TECHNOLOGY CORPORATION
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. The manufacturing method of the power device of claim 10, wherein a bottom and a side of the forward conductive unit are encompassed by a first insulation structure, while, bottoms and sides of the plurality of LIGBTs are encompassed by a second insulation structure; and wherein a method for forming the first insulation structure and the second insulation structure includes:
forming an insulation layer on the semiconductor substrate, wherein the insulation layer is located between and separates the semiconductor substrate and the epitaxial layer, wherein the semiconductor substrate is entirely in contact with and covered by the insulation layer, wherein a part of the insulation layer serves as a first insulation bottom layer of the first insulation structure, whereas, another part of the insulation layer serves as a second insulation bottom layer of the second insulation structure; and
simultaneously forming a first insulation side wall of the first insulation structure and a second insulation side wall of the second insulation structure in the epitaxial layer via a deep trench etching process step and an oxidation deposition process step.