An off-line monitoring method for nitrogen-doped silicon carbide thin films

Abstract

The invention provides an off-line monitoring method for a nitrogen-doped silicon carbide film, and relates to the field of semiconductor integrated circuit manufacturing, in particular to the off-line monitoring method for the nitrogen-doped silicon carbide film. The method includes the following steps that a bare wafer is provided; a layer of silicon dioxide film grows on the bare wafer; a metal layer grows on the silicon dioxide film; sticky pollution on the surface of the metal layer is removed; the nitrogen-doped silicon carbide film is manufactured on the metal layer to form a monitoring wafer; parameters are measured; the monitoring wafer is recovered, and the nitrogen-doped silicon carbide film and the metal layer are removed; the silicon dioxide film is removed to form a bare wafer again; the preceding steps are repeated. By means of the method, direct recovery and use of the off-line monitoring wafer of the nitrogen-doped silicon carbide film on a semiconductor production line can be achieved, recovery cost of the off-line monitoring wafer of the nitrogen-doped silicon carbide film is saved, and a large quantity of standby bare wafers do not need to be stored.

Description

technical field [0001] The invention relates to semiconductor integrated circuit manufacturing technology, in particular to an off-line monitoring method for nitrogen-doped silicon carbide film. Background technique [0002] Nitrogen-doped SiC film (N doped SiC, referred to as: NDC) is often used as a dielectric barrier layer at the back end of an integrated circuit to prevent copper from diffusing into the medium. At present, the off-line monitoring of nitrogen-doped silicon carbide film is to directly grow NDC film on the bare wafer, and then use the corresponding optical measuring machine for testing to monitor the thickness, refractive index and other parameters of the film. However, due to the very stable chemical properties of NDC and insoluble in strong acids (it can be dissolved in strong alkali such as NaOH solution, but strong alkali will contaminate silicon wafers), it is impossible to recycle monitoring wafers in the factory using conventional cleaning processes....

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Problems solved by technology

[0005] Neither of the above two patents can solve the high recycling costs caused by the monitoring wafer being sent out for recycling once it is used, nor can it reduce the factory’s reserve of spare bare die wafers

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