▎ 摘　　要

NOVELTY - Forming inter-gate oxide layer comprises providing a substrate, where the substrate is formed with at least one groove, and the bottom of the groove is provided with a shielding gate structure, performing a deposition etching process cycle to form a first gate oxide layer, covering the shield gate structure and partially filling the trench, performing the first deposition etch process cycle by performing a first deposition process to form the first inter- gate oxide layer material with a predetermined thickness, and removing a portion of the first gate oxide layer material by wet etching, and forming a second inter-graphene oxide layer. USE - Method for forming an inter-gate oxide layer for forming a shielding gate trench type device e.g. power MOSFET device and insulated gate bipolar transistor (IGBT). ADVANTAGE - The problem of uneven surface of the oxide layer between the gate can be solved. The film layer quality of the gate oxide layer can be improved by removing the top surface and the first gate oxide layers of the closing portion. The surface roughness of the shielding gate trench type device can be reduced. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for forming a shielding gate trench type device. DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart of a method for forming an inter-gate oxide layer. Substrate (10) Groove (11) Patterned hard mask layer (12) Shielding gate structure (20) Shielding gate (21) Inter-gate oxide layer (34)