Method for producing a via, a method for producing an array substrate, an array substrate, and a display device

A method for producing an array substrate comprising:

• forming in sequence from bottom to top a metal layer comprising a pattern of a gate line and a gate, a gate insulating layer and an active layer on a substrate base;
• forming a metal layer comprising a pattern of a source and a drain;
• forming a protective layer covering the substrate and a first passivation layer comprising a first via located above the drain and exposing the protective layer;
• forming a metal layer comprising a pattern of a first electrode;
• forming a second passivation layer;
• wherein the method for producing an array substrate further comprises the following steps of:
• producing a second via located above the drain in the second passivation layer;
• and
• forming a metal layer comprising a pattern of a second electrode to realize electrical connection between corresponding electrode patterns,
• wherein producing the second via comprises the following steps of:
• employing a first etching process to partially etch a top film layer in an area that needs to form a via above the drain, wherein the vertical etching amount achieved by employing the first etching process is less than the thickness of the top film layer;
• and
• employing a second etching process for which the vertical etching rate is larger than the lateral etching rate to etch the remaining part in the area that needs to form a via, until the drain is exposed, wherein the top film layer is the second passivation layer.

An array substrate obtained by employing the following production method:

• forming in sequence from bottom to top a metal layer comprising a pattern of a gate line and a gate, a gate insulating layer and an active layer on a substrate base;
• forming a metal layer comprising a pattern of a source and a drain;
• forming a protective layer covering the substrate and a first passivation layer comprising a first via located above the drain and exposing the protective layer;
• forming a metal layer comprising a pattern of a first electrode;
• forming a second passivation layer;
• wherein the method for producing the array substrate further comprises the following steps of:
• producing a second via located above the drain in the second passivation layer;
• and
• forming a metal layer comprising a pattern of a second electrode to realize electrical connection between corresponding electrode patterns,
• wherein producing the second via comprises the following steps of:
• employing a first etching process to partially etch a top film layer in an area that needs to form a via above the drain, wherein the vertical etching amount achieved by employing the first etching process is less than the thickness of the top film layer;
• and
• employing a second etching process for which the vertical etching rate is larger than the lateral etching rate to etch the remaining part in the area that needs to form a via, until the drain is exposed, wherein the top film layer is the second passivation layer.