Aspects of the disclosure provide a semiconductor device. The semiconductor device includes a memory stack of gate layers and insulating layers. The gate layers and the insulating layers are stacked alternatingly and are formed into stair steps in a staircase region. Further, the semiconductor device includes a landing stack formed on the stair steps in the staircase region. The landing stack includes an upper layer that is etch selective to a contact isolation layer that covers the staircase region. Then, the semiconductor device includes a first contact structure on a first stair step of the stair steps. The first contact structure extends through a first contact hole in the contact isolation layer and the landing stack. The first contact structure is connected with a first gate layer (e.g., a top gate layer) of the first stair step.