Photomask manufacturing method

A photomask manufacturing method, comprising:

• providing a substrate structure, wherein the substrate structure comprises:
• an etch material layer;
• a first sacrificial layer on a portion of the etch material layer;
• and
• a photomask layer on an upper surface of the etch material layer, an upper surface of the first sacrificial layer, and a side surface of the first sacrificial layer, wherein the side surface of the first sacrificial layer comprises a first side, a second side opposite to the first side, a third side, and a fourth side opposite to the third side;
• forming a second sacrificial layer covering the photomask layer on the etch material layer and the photomask layer on the side surface of the first sacrificial layer;
• etching the photomask layer not covered by the second sacrificial layer to expose the first sacrificial layer;
• removing the first sacrificial layer and the second sacrificial layer;
• removing the photomask layer on the etch material layer;
• and
• removing the photomask layer on either the first and the second sides, or the third and the fourth sides of the first sacrificial layer.