A MOS transistor may include at least one of: a channel having a width W0 and a length L0; an active area with a channel between a source area and a drain area; a gate insulating layer formed over a channel; and/or a gate conductor formed over a gate insulating layer and intersecting the active area. In embodiments, a gate conductor may include at least one of: a connection pattern formed with a gate contact hole which electrically connects the gate conductor to the outside; an additional pattern connected to a connection pattern and positioned in parallel with both source and drain areas while being spaced apart from the active area at a certain distance; and a channel pattern connected to an additional pattern in the shape of a T and defining the length of a channel.