Active matrix substrate having interleaved source and drain electrodes on circle semiconductor and display device including same

A method of manufacturing an active matrix substrate, the method comprising steps of:

• forming a scanning line on a substrate, the scanning line including a gate electrode;
• forming a thin film transistor including
• forming a circular shaped semiconductor layer above the gate electrode, wherein the shape of the semiconductor layer is obtained by etching a circular resist pattern being circular due to a shape of droplets of ink jet printing,
• forming a source electrode and a drain electrode, wherein the semiconductor layer is formed with a sufficient margin to surround the source electrode and the drain electrode such that the source electrode and the drain electrode overlap with the semiconductor layer;
• forming a signal line that is connected to the source electrode, and that crosses with the scanning line;
• and
• forming a pixel electrode connected to the drain electrode,
• wherein
• the drain electrode extends from the pixel electrode into a drain electrode formation region located to be kept within a semiconductor layer formation region, the drain electrode formation region sandwiched between a plurality of portions of the source electrode,
• the source electrode formed to include two acting parts having strip-like shapes protruding from the signal line, which is parallel to the gate line,
• the drain electrode formed to include an acting part having a strip-like shape which protrudes from the pixel electrode, which is parallel to the gate line, and is sandwiched by the acting parts of the source electrode,
• the gate electrode includes a part having a strip-like shape protruding from the gate line perpendicularly and overlapping with the acting parts of the source electrode and the acting part of the drain electrode,
• wherein the sufficient margin of the semiconductor layer includes a portion of the semiconductor layer that extends from a region that overlaps with substantially the entire area of the source electrode that surrounds the drain electrode to beyond outer edges of the outer perimeter of said area of the source electrode,
• wherein a Cgd region as a region consisting of portions of the drain electrode and the gate electrode that overlap each other is disposed in the central portion of the semiconductor layer having the circular shape, when viewed from the top.