Patent ID: 8991330
Filing Date: 2015-03-31
Classification: B82Y,G03B,G03F,H01J,H01L,Y10T

Abstract:
1. A substrate support structure for clamping a substrate by means of a capillary force created by a liquid clamping layer having a lower pressure than its surroundings and having an outer liquid surface, the substrate support structure comprising a surface provided with a plurality of substrate supporting elements for holding the substrate, the surface of the substrate support structure comprising a perimeter being circumscribed by a moat, and further comprising surface portions with different capillary potential for inducing, during clamping, a predetermined capillary flow within the liquid clamping layer to replenish evaporating liquid at locations within a portion of the surface of the substrate support structure with a higher capillary potential; wherein at least a part of the surface portions with a lower capillary potential takes the form of a channel, wherein the channel extends from a predetermined location along the perimeter, and wherein the channel is arranged to induce a capillary flow from the channel to the periphery of the liquid clamping layer.