A sensing device for measuring a plasma process parameter in a plasma chamber for processing workpieces may include a substrate with one or more sensor embedded in the substrate. The substrate can have a surface made of substantially the same material as workpieces that are plasma processed in the plasma chamber. Each sensor can include a collector portion made of substantially the same material as the substrate surface. The collector portion includes a surface that is level with the surface of the substrate. Sensor electronics are embedded into the substrate and coupled to the collector portion. When the substrate surface is exposed to a plasma one or more signals resulting from the plasma can be measured with the sensor(s).