Phase-change material (PCM) contacts with slot lower portions and contact dielectric for reducing parasitic capacitance and improving manufacturability in PCM RF switches

摘要

In fabricating a radio frequency (RF) switch, a phase-change material (PCM) and a heating element underlying an active segment of the PCM are provided. A contact uniformity support layer is formed over the PCM. The PCM and the contact uniformity support layer are patterned. A contact dielectric is formed over the contact uniformity support layer. Slot lower portions of PCM contacts are formed extending through the contact dielectric and through the contact uniformity support layer, and connected to passive segments of the PCM. Wide upper portions of the PCM contacts are formed over the contact dielectric and over the slot lower portions of the PCM contacts. The contact dielectric separates the wide upper portions of the PCM contacts from the heating element so as to reduce parasitic capacitance of the RF switch. The contact uniformity support layer maintains a substantially constant thickness of the passive segments of the PCM.