Photoresist-removing method

Abstract

The invention discloses a photoresist-removing method, which comprises the following steps of: bombarding a photoresist-removing object by utilizing an O2 (oxygen) plasma and detecting a CO (carbon monoxide) product; stopping the bombardment of the photoresist-removing object by utilizing the O2 plasma when the decreased amount of CO reaches a preset value; and then bombarding the residue in the photoresist-removing object by utilizing a CO2 (carbon dioxide) plasma. The invention can effectively remove the photoresist of the photoresist-removing object, and can reduce the damage to low-k mediums.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a deglue method. Background technique [0002] Interconnects are wires made of conductive materials such as metals such as aluminum, polysilicon, or copper that carry electrical signals to different parts of a chip. Metal wires conduct signals in an integrated circuit (IC, Integrated Circuit), and the dielectric layer can ensure that signals are not affected by adjacent metal wires. Since the dielectric constant of the insulating medium, that is, the smaller the k value, the smaller the electrical coupling loss between adjacent wires, therefore, a medium with a low k value is usually selected as the interlayer dielectric (ILD, InterLayer Dielectric). [0003] After the etching is completed, the photoresist is no longer useful on the surface of the silicon wafer and needs to be removed. There are two methods for removing photoresist: plasma dry method and wet...

AI Technical Summary

Problems solved by technology

However, only using a lower glue removal pressure also has disadvantages: First, the pump power of the machine needs to be large enough to withstand such a low pressure, and the gas flow rate needs to be large to quickly reduce the pressure in the reaction chamber to so low; the second is the low pressure O 2 The flow will enhance the directional bombardment of the plasma, which will cause the loss of the protective layer of low-k materials to a certain extent.

The disadvantage of this is that the glue removal rate is slow, the throughput is low, and the production capacity is affected

[0009] In addition, due to the CO 2 It will not cause damage to the low-k medium, so the existing technology will also use 1-step low-pressure and low-flow CO 2 Plasma degumming method, but the disadvantage of this method is that the reaction rate is low, the time is long, and the particle environment in the reaction chamber is not easy to control, and it is relatively easy to produce a large amount of polycrystalline residues that are not easy to remove

If the k value of the low-k medium is lower such as: k2 ), hydrogen (H 2 ) and other gases, but the degumming rate of these gases is slower, and the reaction chamber environment is more difficult to maintain

Images