Elastic film, bearing head, chemical mechanical polishing system and chemical mechanical polishing method

The invention discloses an elastic film, a bearing head, a chemical mechanical polishing system and a chemical mechanical polishing method, and the elastic film comprises a circular bottom plate which is used for abutting against a wafer; the peripheral arm comprises a vertical part, a first horizontal extension part and a second horizontal extension part, the vertical part vertically extends upwards along the periphery of the bottom plate, the first horizontal extension part horizontally extends inwards along the top end of the vertical part, and the second horizontal extension part horizontally extends outwards along the top end of the vertical part; the first cavity with the first horizontal extending part and the second horizontal extending part as the side walls is used for applying vertically-downward acting force to the vertical part. The elastic film provided by the invention is high in control precision, the possibility of damage is reduced, and an adjustable window of the removal rate is increased,