Method for manufacturing contact window for reducing contact resistance

Abstract

The invention provides a preparation method for a contact window that reduces contact resistance. Firstly, a substrate, on which a protective layer and a dielectric layer are successively formed, is provided. Afterward, a dry etching process is carried out so as to remove a part of the dielectric layer, thus forming an opening which exposes a part of the protective layer. Then, a wet cleaning process is performed. After that, a dry cleaning process is performed so as to remove the protective layer positioned at the bottom of the opening, and a conductor layer is formed in the opening afterward.

Description

technical field [0001] The invention relates to a semiconductor process, in particular to a method for manufacturing a contact window capable of reducing contact resistance. Background technique [0002] With the rapid development of semiconductor process technology, in order to increase the speed and performance of components, the size of the entire circuit components must be continuously reduced, and the integration of components must be continuously improved. In the case of requiring higher and higher integration of components, changes in the physical characteristics of the components (such as contact resistance between components) must also be considered to avoid affecting the operating speed and performance of the components. [0003] Taking memory as an example, a memory cell is usually composed of a transistor and a capacitor. A transistor includes a gate and source / drain regions. The gate of the transistor is electrically connected to a corresponding word line (WL)...

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Problems solved by technology

However, while removing the native oxide layer 114, part of the borophosphosilicate glass layer 106, the silicon oxide layer 108 and the silicon substrate 100 will also be corroded.

In particular, the doped borophosphosilicate glass layer 106 has greater wet etching selectivity than the undoped silicon oxide layer 108, so that the sidewall of the opening 112 will be over-eroded and concave, resulting in The critical dimension (CD) of the subsequent preformed contact window is too large

In addition, if the silicon substrate 100 at the bottom of the opening 112 is corroded by the etchant and dented, it will seriously affect the reliability of the process and the performance of the device.

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