Wafer table chuck having a particle recess

A process tool comprising:

• a chuck having a plurality of first protrusions, a plurality of second protrusions, a third protrusion, and a plurality of particle recesses, wherein the first, second, and third protrusions are laterally spaced from and independent of each other, wherein the first, second, and third protrusions define a top surface of the chuck and protrude from a base surface of the chuck to the top surface of the chuck, wherein the base surface of the chuck is between the top surface of the chuck and a bottom surface of the chuck, wherein the particle recesses extend in to the chuck from the top surface of the chuck to a location between the bottom surface of the chuck and the base surface of the chuck, wherein the first protrusions each extend continuously in a first closed path around a center of the chuck, wherein the second protrusions each extend continuously in a second closed path around the plurality of first protrusions except at the particle recesses, and wherein the third protrusion extends continuously in a third closed path around the plurality of second protrusions.

A method, comprising:

• providing a chuck having a plurality of impressions and a particle recess, wherein the impressions are laterally spaced and extend into the chuck from a top surface of the chuck to a base surface of the chuck, wherein the base surface of the chuck defines bottom surfaces respectively of the impressions, and is spaced between the top surface of the chuck and a bottom surface of the chuck, and wherein the particle recess extends in to the chuck from the top surface of the chuck to a location spaced between the base surface of the chuck and the bottom surface of the chuck;
• and
• positioning a workpiece on the chuck, wherein the workpiece has a workpiece alignment mark within the workpiece, and wherein the workpiece is positioned so the workpiece alignment mark directly overlaps with the particle recess.