Patent ID: 7554120

Claim:
A circuit board for an electro-optical device, comprising: a data line; a gate electrode layer; a pixel electrode; a transistor including: a semiconductor layer including a channel region, a data-line-side source/drain region that is electrically connected to the data line, a pixel-electrode-side source/drain region that is electrically connected to the pixel electrode, a first junction region that is formed between the channel region and the data-line-side source/drain region, and a second junction region that is formed between the channel region and the pixel-electrode-side source/drain region, the channel region, the first junction region, and the second junction region being aligned in a first direction in plan view, and a gate electrode that is a portion of the gate electrode layer located above and overlapping the semiconductor layer; and a first insulator film being interposed between the gate electrode and the semiconductor layer, the first insulator film being formed with an elongated groove, the groove being elongated in the first direction and extending in the first direction along a side of at least a portion of the channel region and the second junction and not extending along the first junction region, an inner groove portion of the gate electrode layer other than the gate electrode extending at least partially inside the groove.