A Method for Optimizing Line Width of Shallow Trench Isolation Etching

Abstract

The invention discloses a method for optimizing the shallow-trench isolation etching line width. The method includes the following steps: measuring the angles of photoresist with different features under different exposure conditions, and building the relation between the measuring results and the shallow-trench isolation etching critical sizes to define the etching time of the shallow-trench isolation etching critical size control step. By means of the method, the angles of the features of the photoresist are measured and quantized through an optical line width measuring apparatus, the etching time of the shallow-trench isolation etching critical size control step is adjusted, the shallow-trench isolation critical sizes are accurately controlled accordingly, the defect that in the past, the shallow-trench line width can only be roughly adjusted according to the line width of the photoresist is overcome, it is guaranteed that the shallow-trench critical sizes are accurately controlled under the condition that the line width and the angles of the photoresist are changed at the same time, and the shallow-trench isolation development efficiency and the product yield are greatly improved.

Description

technical field [0001] The invention relates to semiconductor shallow trench isolation technology, in particular to a method for optimizing the etching line width of shallow trench isolation. Background technique [0002] As the size of semiconductor devices decreases, the critical dimensions of shallow trench isolation are more and more sensitive to the electrical impact of the device and the final yield. [0003] In the process technology of 65nm and below, in order to improve circuit performance and obtain higher device density, shallow trench isolation technology is used and developed. The critical dimension of the trench has an extremely important impact on device electrical and yield: with With the reduction of critical dimensions of semiconductor devices, the size of shallow trench isolation is more and more sensitive to the electrical impact of the device, and in some areas, when the size changes slightly, the electrical properties may change abruptly, such as figur...

AI Technical Summary

Problems solved by technology

[0006] 1) Under different exposure conditions in the working area, the traditional measurement method can only measure the line width of the top of the photoresist, but not the angle of the photoresist, and cannot obtain the relationship between the angle of the photoresist and the critical dimension of the shallow trench;

[0007] 2) When the product is exposed, the line width and angle of the photoresist will be shifted due to the deviation of the exposure machine itself;

[0008] 3) In the process of product etching, due to the change of uncertain factors such as the atmosphere of the etching chamber and parameter drift, it is easy to cause the key dimensions of the top of the trench to deviate from the set specifications;

[0009] 4) When the lithography machine and the etching machine change at the same time, it will lead to the inability to judge the source of the size change of the shallow groove online, and the online products cannot be circulated smoothly, which will bring huge losses to production;

[0010] In the past, the scanning electron microscope is an electron microscope that uses electron beams to scan and excite secondary electron imaging on the surface of the sample. It has the disadvantage that it can only measure the line width and cannot measure the angle of the photoresist, so it cannot accurately feed back the actual information of the photoresist morphology.

Images