collection plate 208 as described below the energy particles that form beam 250 that are not part of the ec particles i e the ions at or below the desired lower energy level for shallow implantation are prevented from emerging from surface 220 and are essentially u201c filtered u201d out by membrane 202 thus only the high energy contaminating particles emerge from the surface 220 of membrane 202 and can be measured directly without any numerical subtraction as mentioned above prior attempts at ec detection required the measuring of the various components of the beam current including for example the total beam and the desired energy level ions and then inferring the ec by subtracting these two quantities in contrast in the present disclosure the role of the subtraction operation is substituted by the physical filtering of the ec particles in the membrane the thickness of membrane 202 may be selected based on an energy of the desired ion beam 250 for a specific implant recipe for fabricating devices on a substrate or wafer for example membrane 202 may have a thickness of approximately 30 nm for detecting ec in a semiconductor fabrication process using an ion beam having an energy of approximately 300 kev and a thickness of approximately 15 nm for detecting ec for a recipe using a 150 kev process membrane 202 may be a diamond like carbon dlc foil such as those available from micromatter of vancouver british columbia canada membranes 202 may be fabricated from other similar materials and have a thickness between approximately 10 nm and approximately 600 nm however membranes 202 having other thicknesses may also be implemented charge collection plate 208 is fabricated from.