Method for improving stability of gate etching morphology and etching equipment

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 a