In some embodiments, the process chambers 140 are plasma process chambers, deposition process chambers, diffusion chambers, or the combination thereof. The plasma process chamber is configured to operate a dry etching process including, for example, a reactive ion etching (RIE) process. The plasma process chamber provides reactive ion gas so as to react with material layers or the wafer. The deposition process chamber provides a vapor phase of a material including any operations such as, but not limited to, chemical vapor deposition (CVD) and physical vapor deposition (PVD). A material layer can be deposited on the wafer in the deposition process chamber. The diffusion chamber provides a thermal process such as a rapid thermal annealing or a laser annealing. A deposited layer can be annealed in the diffusion chamber. The amount and the configuration of the process chambers 140 shown in FIG. 1 are given for the illustrative purposes. Various amounts and the configuration of the process chambers 140 are within the contemplated scope of the present disclosure.

At least one of the process chambers 140 in the multi-chamber system 100 is deposition process chamber configured for performing a deposition process. For illustration in FIG. 1, the deposition process chamber is connected with the buffer chamber 130. In some embodiments, the wafer is transferred from the buffer chamber 130 to the deposition process chamber by the robot blade 132. After the deposition process performing in the deposition process chamber, the wafer is returned to the buffer chamber 130 by the robot blade 132.