Techniques for processing a substrate

A system for processing one or more substrates, the system comprising:

• an ion source for generating ions of desired species, the ions generated from the ion source being directed toward the one or more substrates along an ion beam path;
• a substrate support for supporting the one or more substrates;
• a mask disposed between the ion source and the substrate support, the mask comprising fingers defining one or more apertures through which a portion of the ions traveling along the ion beam path pass and implanted into the one or more substrates;
• and
• a first detector for detecting ions, the first detector being fixedly positioned relative to the one or more substrates,
• wherein the mask and the first detector are positioned relative to one another such that the first detector is directly behind one of the fingers of the mask and removed from a line-of-sight of the ions by the one of the fingers of the mask if the mask and the one or more substrates are aligned, wherein the one of the fingers directly in front of the first detector blocks and prevents the ions from impinging on the first detector if the mask and the one or more substrates are aligned.