Cleaning method after opening etching

Abstract

The invention provides a washing method after etching openings. The method comprises the steps of providing a semiconductor substrate with a dielectric layer, etching openings to form at least one opening in the dielectric layer, carrying out a nitrogen treatment process to wash C-F polymer residue in the opening and finally carrying out a wet washing process.

Description

technical field [0001] The invention provides a cleaning method after opening etching, especially a cleaning method using an in-situ nitrogen treatment process. Background technique [0002] Copper dual damascene (dual damascene) technology with low dielectric constant (low-k; k≤2.9) dielectric layer is currently known as the best metal inner layer for high-integration, high-speed logic integrated circuit chip manufacturing and semiconductor processes below 0.13 microns Wired solutions. The reason is that copper has low resistance value (30% lower than aluminum) and preferred anti-electro-migration resistance (electro-migration resistance), and the dielectric layer material with low dielectric constant can help reduce the resistance between metal wires - Capacitance Time Delay (Resistance-Capacitance Time Delay), it can be seen that the dielectric layer material with low dielectric constant and the copper metal dual damascene interconnection technology are increasingly impo...

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Problems solved by technology

[0008] However, the above use contains both hydrogen / oxygen / carbon tetrafluoride (CF 4 ) plasma cleaning method, or only hydrogen plasma cleaning method, but still cannot effectively remove the residual polymer or metal residue, so it has not been able to make a breakthrough in increasing the process yield (yield)

Therefore, after the known plasma cleaning method, it is often necessary to use multiple wet cleaning processes to remove these residual polymers or metal residues; however, adding multiple wet cleaning processes will greatly reduce the efficiency of the process. throughput and increase process cost

Furthermore, using plasmas containing reactive gases such as hydrogen or carbon tetrafluoride (CF 4 ), etc., this cleaning method tends to damage the low-permittivity dielectric layer, or cause a change in the dielectric constant (k) value of these low-permittivity dielectric layers, thereby affecting the capacitance of the relative component (capacitance)

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