Display device and manufacturing method thereof

A display device comprising:

• a base layer;
• a circuit layer disposed on the base layer;
• and
• a light emitting element disposed on the circuit layer;
• wherein the circuit layer includes:
• at least one organic insulating layer in which a contact hole is defined;
• and
• a connection electrode, a portion of which is disposed in the contact hole, wherein the contact hole includes:
• a first contact hole part having a first inclination measured from a vertical imaginary axis;
• and
• a second contact hole part defined on the first contact hole part and having a second inclination measured from the same vertical imaginary axis greater than the first inclination, and
• wherein a minimum value of a width in one direction of the first contact hole part is about 1.8 micrometers or more and less than about 2.5 micrometers.

A method of manufacturing a display device, the method comprising steps of:

• forming a lower connection electrode;
• forming an organic insulating layer covering the lower connection electrode;
• and
• forming a contact hole in the organic insulating layer to expose a portion of the lower connection electrode,
• wherein the forming of the contact hole is accomplished by steps of:
• forming an inorganic layer on the organic insulating layer;
• etching the inorganic layer to form an inorganic pattern layer in which an opening is defined;
• and
• etching the organic insulating layer using the inorganic pattern layer as a mask.