Method for improving stability of gate etching morphology and etching equipment

Abstract

The invention provides a method for improving the stability of gate etching morphology and etching equipment. The method comprises the steps of providing a substrate, and sequentially forming a gate material layer and a hard mask layer on the substrate; carrying out BT etching according to the first technological parameter, and carrying out OCD measurement to acquire a first measurement angle; carrying out ME etching, wherein technological parameters of ME etching are adjusted according to the first measurement angle, and OCD measurement is carried out after ME etching to obtain a second measurement angle; carrying out SL etching to form a gate, wherein technological parameters of SL etching are adjusted according to the second measurement angle, and OCD measurement is carried out after SLetching to obtain a third measurement angle; and then feeding back the process parameters and the measurement angle of each test step to the next gate etching. According to the invention, the OCD measurement is carried out after each step of the gate etching process, and the process parameters of the next etching step are adjusted according to the angle of the OCD measurement, so that the stability of the gate etching morphology is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method and etching equipment for improving the stability of gate etching morphology. Background technique [0002] With the rapid development of semiconductor manufacturing technology and the continuous shrinking of critical dimension (CD), the performance requirements of semiconductor manufacturing equipment are increasing, and the consistency between wafers and the stability of etching have stricter evaluation standards. . Especially when it comes to the critical gate etching process, the stability of gate morphology will directly affect the stability of Wafer Acceptance Test (WAT). [0003] In the existing gate etching process, the measurement step of the OCD angle (Optical CD angle) is usually carried out after all the etching steps of the polysilicon gate are completed, and the requirements for the stability of the etching equipment and the process window are very ...

AI Technical Summary

Problems solved by technology

As the line width continues to shrink, the existing gate etching process cannot meet the higher process requirements

Taking the 55nm gate etching process as an example, the main etching steps that affect the gate morphology are initial etching (Break Through, BT), main etching (Main Etch, ME) and soft etching (Soft Landing, SL). ), if the OCD angle measurement is performed after all the etching steps are completed, the morphology of the gate cannot be controlled during the etching process, resulting in a decrease in the stability of the gate morphology, which cannot meet the process requirements

Images