Back- Test Structures for Electromigration in chips
FABRICATION OF CALIBRATION BLOCKS FOR ARAMIS 3D IMAGE CORRELATION FOR MEMS DEVICES
The calibration blocks were made using optical lithographic technique, were Laser Pattern Generator was used to define pattern on to a Mask. A mirror image of the Circular Patterns similar to the calibration blocks were first drawn using one of the software called SYMBAD, software developed by from Cadence Design Systems, Inc. The pattern was then transferred onto the mask using Laser Pattern Generator. The glass-mask used was chrome plated. Once the pattern was imprinted onto the mask, it was developed. The resist used on the mask was a positive resist and hence the patterned area resist was removed. This was followed by chrome stripping which helped to give a transparent circular pattern on to the mask. Hence once light is flashed from the back of mask this circular patterned areas will be the bright area (white region) and the remaining area will the dark area for the calibration block as shown in fig2.
Fig. 1 (a) Schematic of the pattern generated onto the mask by laser pattern generator (b) Pattern on individual calibration blocks.
Result:
Three calibration blocks of 2mm, 3mm and 5mm size were fabricated using the above technique
Fig 2: The calibration block