Method of producing semiconductor wafer

Claim 1

A method of producing a semiconductor wafer comprising the steps of: (a) a production process comparing/calculating step for comparing a production plan, which has been prepared in advance, with production achievement data, and subsequently calculating a production progress, (b) a fabrication device status monitor step for monitoring the processing status of fabrication devices, (c) an inventory control step for controlling semiconductor wafers that have been placed on process shelves to be processed in said fabrication devices, and, (d) a process shelf controller step for automatically searching said process shelves for a next semiconductor wafer to be processed by said fabrication devices, whereby calculation of said production progress of step (a) is started in response to a timing signal from step (b), said production progress being used to determine said next semiconductor wafer to be processed, such that step (d) enables the searching of said process shelves for said next semiconductor wafer, wherein if more than one suitable candidate for said next semiconductor wafer is located on the process shelves for said fabrication device, a priority determination is made whereby a ratio is calculated for each candidate wafer and the candidate wafer with the largest corresponding ratio is given highest priority and the candidate wafer with the smallest ratio is given lowest priority, all candidate semiconductor wafers with intermediate ratios being given a priority accordingly, said ratio being calculated by dividing the difference between actual process time for the wafer, including fabrication device set up time, and the planned process time, given by said production plan, by the difference between the planned delivery time, also given by said production plan, and said planned process time.

Claim 2

A method of producing a semiconductor wafer comprising the steps of: (a) a production process comparing/calculating step for comparing a production plan, which has been prepared in advance, with production achievement data, and subsequently calculating a production progress, (b) a fabrication device status monitor step for monitoring the processing status of fabrication devices, (c) an inventory control step for controlling semiconductor wafers that have been placed on process shelves to be processed in said fabrication devices, and, (d) a process shelf controller step for automatically searching said process shelves for a next semiconductor wafer to be processed by said fabrication devices, whereby calculation of said production progress of step (a) is started in response to a timing signal from step (b), said production progress being used to determine said next semiconductor wafer to be processed, such that step (d) enables the searching of said process shelves for said next semiconductor wafer, wherein if more than one suitable candidate for said next semiconductor wafer is located on the process shelves for said fabrication device, a priority determination is made whereby a ratio is calculated for each candidate wafer and the candidate wafer with the largest corresponding ratio is given highest priority and the candidate wafer with the smallest ratio is given lowest priority, all candidate semiconductor wafers with intermediate ratios being given a priority accordingly, said ratio being calculated by dividing the difference between actual process time for the wafer, including fabrication device set up time, and the planned process time, given by said production plan, by the difference between the planned delivery time, also given by said production plan, and said planned process time.