Patent ID: 6363294
Filing Date: 2002-03-26
Classification: G03F,H01L

Abstract:
In a method for real-time in-situ interactive supervision of a particular step of a process for fabricating a semiconductor wafer belonging to a batch of wafers comprising the steps of:a) selecting at least one process parameter that is determining for the monitoring of the particular step; b) establishing a database including: a first file referred to as an â€œalarmâ€  component of the database which contains in coded form: an evolution of said selected process parameter in normal operating conditions and in all deviations thereof based on expert information; algorithms representative of analysis rules adapted to recognize any such deviation which include rejection criteria for each deviation; and, an alert code for each case of deviation; a second file referred to as a â€œwafer historyâ€  component of the database which contains in coded form a history of the wafer until the particular step with a reference to the batch, the process and step names for the particular step and an identification number of the wafer in consideration; wherein said wafer history includes important process parameters and the evolution of said selected process parameter for the previous process steps for the wafer in consideration; c) providing process elements including: a tool having at least one chamber for processing the wafer at said particular step of the fabrication process; a tool computer to control physical process parameters of the tool; at least one monitoring equipment to monitor at least one selected process parameter that is determining for said step; at least one measurement unit internally mounted in the monitoring equipment and/or in the process tool that is capable to perform in-situ process parameter measurements; a supervisor that is connected through a network to said tool computer, said monitoring equipment, said measurement unit and said database to supervise the process flow for said determined step; d) introducing the wafer in the tool chamber; e) in-situ measuring a determined process parameter with said measurement unit to obtain a measurement value, the value being stored in the database for immediate or subsequent use; f) retrieving the value from the database for immediate exploitation in said determined step to up-date at least one process parameter to change operating conditions thereof; g) starting wafer processing; h) analyzing the evolution of said selected process parameter by the supervisor for comparison with corresponding data stored in the database to detect in real-time in-situ any deviation that could occur during said particular step; i) continuing wafer processing to normal end if no deviation is detected, or taking a corrective action as initiated by the supervisor if a deviation is detected, wherein the supervisor provides the alert code corresponding to the detected deviation; and, j) storing all data that are representative of the processing for said determined step in a â€œstep reportâ€  and any alert code in an â€œalarm reportâ€  to up-date the wafer history file of the wafer in consideration.