Specific Process Knowledge/Lithography/DUVStepperLithography/Reticle Design

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Reticle Design

A DUV reticle is needed that should be designed by the customer. Please note that the projection magnification of the stepper is 1:5, so that the dimensions of the pattern on the reticle are expanded by a factor 5 with respect to those printed on the wafer.

The whole reticle can be regarded as one chip that might be printed one time onto the wafer or repeatedly - step-by-step - in a two dimensional array. Alternatively, different chips can be placed onto the reticle, separated by frames. These chips can be printed individually onto the wafer either as one chip or as an array. Then the individual chips of the design have to be surrounded by frames. Additionally, the pattern of two or more different reticles can be combined on one wafer.

If the pattern of the reticle must be aligned to another one - that is already located on the wafer - the wafer will need to be equipped with several alignment marks(one TVPA mark and two AGA marks in x and y direction), preferable for every chip. The stepper can only recognize the approved alignment marks Therefore use only these marks as TVPA Media:TVPA_Small_Line_Mag5_P.pdf‎ and AGA Media:20P4_F_Mag5_P.pdf .

A guide for preparing reticle files for the Canon FPA-3000EX4 stepper, having the correct dimensions and positions of the individual patterns, frames and alignment marks can be found here: Media:Canon_Stepper_Reticle_Guide_v0_03.pdf.

Usually the reticle is fabricated by an external company. It is recommended to send the mask design in GDS format to the Photolith group of Nanolab, so that they can verify the mask design and order the mask.