In some embodiments, at least one of the layers 510, 520, 530, and 540 is formed and/or measured by some operations of the method 400 shown in FIG. 4. For example, the layer 530 is formed by the operation S410 of the method 400. The layer 530 is deposited on the layer 520. The thickness of the deposited layer 530 is then measured by the operation S414 of the method 400, before forming the next layer 540, and then the state of the deposition process of layer 530 is identified. In some embodiments, when the state of the deposition process of layer 530 is “PASS,” the flow of forming the semiconductor device 500 is proceeded to the next process. In some other embodiments, when the state of the deposition process of layer 530 is “FAIL,” the layer 530 may not satisfy the requirements to form the semiconductor device 500.

In some embodiments, a system includes a factory interface, a deposition tool, and at least one measuring device. The factory interface is configured to carry a wafer. The deposition tool is coupled to the factory interface and configured to process the wafer transferred from the factory interface. The at least one measuring device is equipped in the factory interface, the deposition tool, or the combination thereof. The at least one measuring device is configured to perform real-time measurements of a thickness of a material on the wafer that is carried in the factory interface or the deposition tool.