Electrostatic wafer handling for thin wafer processing

Mobile electrostatic carriers, so called e-carriers, offer a new and promising technical solution for simple and reversible attachment of thin wafers onto support substrates. The paper reports on latest developments in manufacture of e-carriers based on silicon wafers with through substrate vias and backside contact pads. Thermal and electrical characterizations of e-carries have proven very low leakage currents at temperatures up to 300degC. These new types of e-carriers enable long term electrostatic holding capabilities. It is also shown that electrical properties of transistor devices are not changed when CMOS wafers are attached onto e-carriers, neither in face up nor face down attachment configuration. Furthermore, the paper proposes a technical concept how electrostatic support technique can be used for thin wafer processing in wet-chemical environments. E-carriers can also be applied for reversibly bonding of single chip devices onto a carrier substrate. The paper explains how this feature can be used in chip to wafer stacking for 3d integrated systems.