Some embodiments of the present disclosure are directed to an embedded flash (e-flash) memory device that includes a flash memory cell and a metal-oxide-semiconductor field-effect transistor (MOSFET). The flash memory cell includes a control gate disposed over a floating gate. The MOSFET includes a logic gate disposed over a gate dielectric. The floating gate and a first gate layer of the logic gate are simultaneously formed with a first polysilicon layer. A high temperature oxide (HTO) is then formed over the floating gate with a high temperature process, while the first gate layer protects the gate dielectric from degradation effects due to the high temperature process. A second gate layer of the logic gate is then formed over the first gate layer by a second polysilicon layer. The first and second gate layers collectively form a logic gate of the MOSFET.