The implementations described herein generally relate to a sensing device for use in the semiconducting industry, which sense process parameters to control semiconductor processes. More specifically, the implementations relate to packaging for a surface acoustic wave (SAW) based devices or wireless or RF-responsive sensors for use in the harsh processing environments of a semiconductor processing chamber such that the neither the sensor and its components nor the chamber components interfere with or contaminate one another. The sensor packaging may include various packaging layers with or without protective coatings and a waveguide. The packaging may have a thickness chosen such that the thickness is less than the electromagnetic wavelength of a SAW sensor radio wave. The sensing devices may be disposed in cavities of the chamber, the processing volume, on chamber components, and/or on the substrate.