A semiconductor structure includes a split gate nonvolatile memory cell and a high voltage transistor. The nonvolatile memory cell includes an active region, a nonvolatile memory stack provided above the active region, a control gate electrode provided above the memory stack, a select gate electrode at least partially provided above the active region adjacent to the memory stack and a select gate insulation layer. The high voltage transistor includes an active region, a gate electrode and a gate insulation layer provided between the active region and the gate electrode. The select gate insulation layer of the nonvolatile memory device and the gate insulation layer of the high voltage transistor are at least partially formed of a same high-k dielectric material. The select gate electrode of the nonvolatile memory device and the gate electrode of the high voltage transistor are at least partially formed of a same metal.