NOVELTY - The method comprises loading first and second process wafers, first and second control wafer and a dummy wafer (1032) into a chamber (101), depositing an amorphous silicon layer on the first and second process wafers, removing the first and second process wafer and the first and second control wafer from the chamber, and dry cleaning the chamber and the dummy wafer. The method is controlled by a computer system. The dummy wafer includes a silicon oxide layer. The method further comprises: loading the dummy wafer, the process wafers and the control wafers onto a vertical boat (102).    USE - The method is useful for depositing an amorphous silicon layer (claimed) on wafers for electronic devices such as solar cell, MOSFET, image sensor and micro-electro-mechanical system.    ADVANTAGE - The method is capable of improving the stable thickness and maintaining particle free in the deposition of the amorphous silicon layer thus reducing the thermal stress which is the root cause of crack and peeling and preventing current leakage.    DETAILED DESCRIPTION - The method comprises loading first and second process wafers, first and second control wafer and a dummy wafer (1032) into a chamber (101), depositing an amorphous silicon layer on the first and second process wafers, removing the first and second process wafer and the first and second control wafer from the chamber, and dry cleaning the chamber and the dummy wafer. The method is controlled by a computer system. The dummy wafer includes a silicon oxide layer. The method further comprises: loading the dummy wafer, the process wafers and the control wafers onto a vertical boat (102); issuing by the computer system a control job comprising a first process job and a second process job, where the first process job is to deposit the amorphous silicon layer on the process wafers, and the second process job is to dry clean the chamber and the dummy wafer; depositing the amorphous silicon layer on the process wafers according to the first process job; removing the process wafers and the control wafers from the chamber; and dry cleaning the chamber and the dummy wafer according to the second process job. The dummy wafer, the process wafers, and control wafers are loaded onto the vertical boat for completely filling the vertical boat. The amorphous silicon layer is deposited using silicon hydride and a doping gas under a temperature of 200-500 degrees C. The step of dry cleaning is performed using a fluorine clean gas under a pressure of less than or equal to 100 mTorr. A first recipe is used by a computer system to control depositing the amorphous silicon layer. A second recipe is used by the computer system to control dry cleaning the chamber and the dummy wafer. The computer system selects a dry cleaning recipe, and executes the dry cleaning recipe for dry cleaning the chamber and the dummy wafer.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a semiconductor process system for depositing an amorphous silicon layer on wafers controlled by a host computer system.    Chamber (101)    Vertical boat (102)    Process wafer (1031)    Dummy wafer (1032)    Control wafer. (1033)