Mask assembly, apparatus, and method of manufacturing display apparatus

1. A method of manufacturing a display apparatus, the method comprising:

arranging a deposition source, a mask assembly, and a substrate such that the deposition source faces the mask assembly and the mask assembly faces the substrate; and

depositing a deposition material on the substrate by at least one of evaporating the deposition material from the deposition source and passing the deposition material through the mask assembly and sublimating the deposition material from the deposition source and passing the deposition material through the mask assembly,

wherein the mask assembly comprises:

a mask frame; and

a mask sheet arranged on the mask frame and comprising a pattern portion configured to allow a deposition material to pass through an opening of the pattern portion, and wherein the pattern portion is recessed from a surface of the mask sheet and has an outermost portion that comprises at least two steps, the two steps comprising a first step having a first uniform thickness and a second step having a second uniform thickness, wherein a boundary of the pattern portion is a zigzag pattern in at least one of a longitudinal direction of the mask sheet and a width direction of the mask sheet.

2. The method of claim 1 , wherein the pattern portion is formed by a laser beam.

3. The method of claim 2 , wherein: the pattern portion is produced by moving the mask sheet multiple times and forming each of a plurality of process regions after each time the mask sheet is moved such that the plurality of process regions are connected to each other.

4. The method of claim 3 , wherein each of the plurality of process regions comprises a rhombus shape.