Window tiles for electron beam systems are provided. The window tiles can comprise a first surface and a second surface, and one or more features extending from the first surface to the second surface. The one or more features can have a non-uniform or tapered cross-section between the first surface and the second surface. The first surface can be configured to be exposed to vacuum conditions and can be configured to receive electrons accelerated from an electron beam generator. The second surface can be configured to allow electrons to pass through to a foil. The window tiles can improve electron beam processing systems for example by increasing electron throughput, lowering power consumption, reducing heat absorption to the foil, improving and increasing foil life, and potentially allowing for use of smaller and cheaper machines in electron beam processing.