Array substrate of liquid crystal display and fabrication method thereof

A method of fabricating an array substrate of an LCD, the method comprising:

• forming an active layer on a substrate using a first mask process;
• depositing a first insulating layer and a first metal layer on the substrate including the active layer and patterning the first metal layer using a second mask process to form a gate electrode;
• forming a source region and a drain region on predetermined regions of the active layer by implanting impurity ions into the predetermined regions of the active layer;
• depositing a second insulating layer and a transparent conductive film on an entire surface of the substrate including the gate electrode, and removing portions of the first and second insulating layers and the transparent conductive film using a third mask process to form first and second contact holes partially exposing the source and drain electrodes, and a pixel electrode;
• and
• depositing a second metal layer on the substrate and patterning the second metal layer using a fourth mask process to form a source electrode and a drain electrode, such that the source electrode is connected to the source region through the first contact hole and the drain electrode is connected to the drain electrode through the second contact hole.

A method of fabricating an array substrate of an LCD, the method comprising:

• providing a substrate having an insulating layer overlying a patterned metal layer;
• forming a resist layer overlying the insulating layer;
• and
• aligning a mask to the substrate,
• wherein the mask has a variation in diffraction density, and
• wherein the mask is aligned such that an area of high diffraction density is in spaced relationship with the patterned metal layer.