Semiconductor process

A semiconductor process including the following steps is provided. A substrate is provided. The substrate includes an active region. A gate is formed on the substrate in the active region. The gate and the substrate are isolated from each other. A block layer is formed on the substrate. The block layer is located in the active region. There is spacing between the block layer and the gate. A tilt angle ion implantation process is performed on the substrate by using the block layer as a mask to form a pocket region in the substrate at two sides of the gate. A dopant concentration of the pocket region formed by the tilt angle ion implantation process is adjusted by the spacing between the block layer and the gate.