Design a photomask in KLayout for an ECoG microelectrode array, compose of 16 electrodes (4x4 array). The Mask should be composed of 3 layers that will allow 3 specific photolithography steps:

The 1st layer (first insulation layer) will be used to pattern the SU-8 insulator, shaping the device layout (negative photolithography), using direct-writing mask less photolithography, i.e. the light write the area that need to be cross-linked.

The 2nd layer will be use for the patterning of the positive resist (AZ P4620) that will be used as sacrificial layer for the metal lift off (that will define the metal electrodes, traces, and interconnection). Again, using direct-writing mask less photolithography, i.e. the light write the area that need to be cross-linked.

The 3rd layer will be used for the patterning of the SU-8 insulator of the same shape of the first layer that will be open only on the electrodes and pads to be connected to the characterization/recording system. Also this step will be performed using direct-writing mask less photolithography, using direct-writing mask less photolithography, i.e. the light write the area that need to be cross-linked.

Please show images/steps for each of the three layers and explain the reasoning behind it. Thank you!