APPARATUS FOR SUPPORTING SUBSTRATE PREVENTING IMPURITIES FROM INCOMING INTO STEP PORTION BETWEEN STAGE AND CHANNEL BY FORMING COVERS

PURPOSE: An apparatus for supporting a substrate is provided to prevent a loss of channel and improve stability of the stage. CONSTITUTION: A base(210) having a channel(212) is extended in the direction of X-axis, the channel is provided with a step portion(214) formed in the horizontal direction. A stage(220) is provided with a lower structure(222) and a upper structure(224), and a substrate(10) is supported by the upper structure. An air bearing(226) injecting air to the step portion for floating the stage from the step portion is jointed to the stage. The stage is driven by a driving unit(230). A pair of covers(240) preventing impurities from incoming into the step portion of the channel are extended horizontally adjacent to the upper structure of the stage in each side of the channel.