Etching time detection method and system thereof

Abstract

The invention relates to an etching time detection method, which comprises the following steps of: executing an etching process according to formula data; receiving the light transmittance values transmitted by the plurality of groups of light sensing elements within the judgment time in the etching time; according to the formula data, respectively capturing a plurality of light transmittance values transmitted by each group of light sensing elements to generate a plurality of corresponding calculation values; processing the calculated numerical values within the judgment time to generate numerical value distribution data of the corresponding groups of light sensing elements; and comparing the numerical distribution data to determine an over-etching time. In addition, the invention also provides an etching time detection system.

Description

technical field [0001] The present invention relates to a process method and process system, and in particular to an etching time detection method and an etching time detection system for wet process. Background technique [0002] In wet process etching (wet additional etching process or wet etching process), the higher the concentration of the process (process) solution or the higher the temperature, the faster the film on the substrate will be removed, but excessive etching If the etching rate is too high, it will cause serious under-cutting, or if the etching rate is too low, it will cause under-etching and partially complete the phenomenon. Therefore, the etching rate must be properly controlled. [0003] Furthermore, the time of etching (additional etching or etching) is related to the etching rate of the film material by the process solution. In order to avoid the uneven etching rate, an over-etching process is required to remove the remaining film. Now The existing t...

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Problems solved by technology

[0002] In wet process etching (wet additional etching process or wet etching process), the higher the concentration of the process (process) solution or the higher the temperature, the faster the film on the substrate will be removed, but excessive etching If the etching rate is too high, it will cause serious under-cutting, or if the etching rate is too low, it will cause under-etching and local completion. Therefore, the etching rate must be properly controlled.

[0003] Furthermore, the time of etching (additional etching or etching) is related to the etching rate of the film material by the process solution. In order to avoid the uneven etching rate, an over-etching process is required to remove the remaining film. Now The existing technology is to perform the over-etching process after setting a fixed time, but due to changes in other parameters in the process (such as: the object to be etched, the temperature in the chamber, the concentration of the chemical solution, the degree of inclination of the substrate or the plate surface residual liquid) and often have residual film thickness unevenness during etching

In the existing technology, engineers adjust the formula by replacing the process solution according to their rules of thumb to keep the over-etching time within a certain control range, but different products have different over-etching times, and the above-mentioned rules of thumb cannot be used to replace, or Engineers must control the quality of the process solution according to the product characteristics; or, even for the same product, when the process solution decays, the judgment point of the over-etching time will shift (shift), so it is impossible to accurately judge the start time of the over-etch , resulting in excessive etching or incomplete etching, which will affect product quality and yield (pass rate), and also increase the difficulty of process monitoring and process liquid operation, and take a long time

[0004] In addition, when the existing technology detects the substrate, the film thickness of the substrate will change continuously during the etching process, and how to effectively interpret the effective signal is also a big problem

Or, the existing technology is easily affected by the spray solution or the water vapor remaining on the substrate, resulting in receiving invalid optical noise, and if the substrate swings from side to side or the placement or inclination of the substrate, it will also cause invalid light noise. Feedback of detection signals, so these situations will cause difficulty in interpreting effective detection signals, thereby reducing the judgment of etching time detection

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