Flat structures
Especially for the nearfield scanning optical microscopy we developed a process which makes the fabrication of structures with optical contrast but no topography possible.
 
Test sample for nearfield scanning optical microscopy (NSOM)
  NSOM testsample
 
The test sample which has been developed for NSOM consists of a grid made of wolfram silicide embeded in silicon nitride. Having grid wires with a hight of about 100 nm the final topography between the two different materials is less than 5 nm.