Method for detecting whether wafer position inclines during baking process

Abstract

The invention relates to a method for detecting whether a wafer position inclines or not during the baking process. The method comprises the following steps of monitoring temperature change situation of a hot plate during the baking process of a wafer to be detected, and generating a time curve reflecting the temperature change situation of the hot plate; and comparing the time curve with the already-had normal time curve of a similar type, and judging whether the position of the wafer to be detected inclines or not. By the method, the wafer of which the position inclines is randomly monitored in real time, the scrapped rate caused by unfavorable wafers is reduced, and the method is convenient in detection and high in accuracy; and moreover, a position inclination sensing device is not needed to be arranged, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor photolithography, in particular to a method for detecting whether the position of a wafer is tilted during a baking process. Background technique [0002] In the photolithography process, in order to precisely control the pattern size, the accuracy and uniformity of the baking temperature of the photoresist coated on the wafer are very high. However, if the position of the wafer is tilted during the baking process, the wafer is heated unevenly, which will lead to uneven baking temperature of the photoresist coated on the wafer. Therefore, it is very important that the position of the wafer is not tilted during the baking process. [0003] Most of the baking chambers of existing glue-coating and developing machines do not have wafer position tilt sensing devices, and the machine will alarm only when the wafer position is tilted to a serious degree; only a few are equipped with wafer position...

AI Technical Summary

Problems solved by technology

The actual practice is to pre-set the pressure and time thresholds of the moment the wafer is placed as the alarm parameters of the machine. However, when the wafer is placed on the hot plate for different types of wafers, the pressure change curve with time is different. It is difficult to take into account the uniform setting of the threshold. If the setting is too strict, there will be too many false alarms, which will affect the normal use of the machine. If the setting is too loose, it will not be able to monitor the tilt of the wafer.

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