A mobile, transportable, unipolar electrostatic chuck for clamping thin wafers is described, which avoids unintentional discharging of the package of Mobile Chuck and wafer during wet processing. Short circuits between the contact holes of the chuck and the clamped wafer can lead to the loss of clamping force. A pn-junction within the semiconductor substrate material electrode of the chuck is disclosed, which is using a diode effect to avoid the loss of charges. Dielectric protection layers of PTFE, Y.sub.2O.sub.3 or ferroelectric materials can be used to cover the open contacts of the chuck. This enables the application of Mobile Chucks also for wet etch-, photo- and cleaning processes. Mobile Chucks are made of semiconductor material and semiconductor manufacturing processes are applied. Those Mobile Chucks have nearly identical properties as the clamping substrate itself. This reduces the risk of cross-contamination, particle generation and the risk of mechanical stress due to different coefficients of thermal expansion.