Embedded microelectromechanical systems (MEMS) semiconductor substrate and related method of forming

An embedded MEMS semiconductor substrate is set forth and can be a starting material for subsequent semiconductor device processing. A MEMS device is formed in a semiconductor substrate, including at least one MEMS electrode and a buried silicon dioxide sacrificial layer has been applied for releasing the MEMS. A planarizing layer is applied over the substrate, MEMS device and MEMS electrode. A polysilicon protection layer is applied over the planarizing layer. A silicon nitride capping layer is applied over the polysilicon protection layer. A polsilicon seed layer is applied over the polysilicon nitride capping layer. The MEMS device is released by removing at least a portion of the buried silicon dioxide sacrificial layer and an epitaxial layer is grown over the polysilicon seed layer to be used for subsequent semiconductor wafer processing.