The present disclosure provides an embodiment of a fin-like field-effect transistor (FinFET) device. The device includes a substrate having a first gate region, a first fin structure over the substrate in the first gate region. The first fin structure includes an upper semiconductor material member, a lower semiconductor material member, surrounded by an oxide feature and a liner wrapping around the oxide feature of the lower semiconductor material member, and extending upwards to wrap around a lower portion of the upper semiconductor material member. The device also includes a dielectric layer laterally proximate to an upper portion of the upper semiconductor material member. Therefore the upper semiconductor material member includes a middle portion that is neither laterally proximate to the dielectric layer nor wrapped by the liner.