Resolution targets are made of 1 to 2.5-um-thick gold patterns on silicon nitride membranes of size 1 mm x 1 mm. The pattern is reproduced 9 times on every membrane. The nitride membrane can be removed on request, to leave free-standing gold structures. Chip sizes are 5 mm x 5 mm. Each target contains:

​A wagon wheel central           4 USAF 1951 resolution               4 linear grating regions with horizontal and

structure                                        patterns                                             vertical lines

4 linearly variable pitch rulers on              4 variable pitch, corner-to-corner structures

the sides of each target                               at 45 o in the corners of each target


Feature sizes are between 0.5 um and several um.