Method and structure for forming barrier layer

Abstract

The invention is a method of forming blocking layer, firstly making a double inserted structure on a metallic layer, where the structure contains a first dielectric layer and a second one, the former containing a hole and the latter containing a groove, successively forming a first tantalum metal layer on the structure, then forming a tantalum nitride layer on the first tantalum metal layer, eliminating the tantalum metal layer above the bottom of the hole in the first dielectric layer in an ion spattering mode, where the tantalum atoms in the eliminated tantalum nitride layer will deposit on the side wall of the hole in the first dielectric layer, and finally forming a second tantalum metal layer on the remained tantalum nitride layer, where there are only the first and second tantalum metal layers above the bottom of the hole, and the made blocking layer will have lower resistivity at the bottom of the hole and an ability to completely block copper atoms from diffusing to the dielectric layer.

Description

(1) Technical field [0001] The present invention is a semiconductor manufacturing method, especially a method of manufacturing an internal barrier layer of a damascene structure. (2) Background technology [0002] In the semiconductor manufacturing process, after the active components of the semiconductor components above the substrate are fabricated, the next step is to fabricate the metal wires above the active components of the completed semiconductor components to complete the internal circuit connection of the semiconductor components to be fabricated. Wire. In the manufacturing process of the above-mentioned metal wires, a metal layer is usually first formed above the active element of the semiconductor element, and then the first layer of metal layer is completed by photoresist, lithography, and etching, and then the first layer of metal layer A layer of dielectric layer is deposited on the top, corresponding to the needs of different semiconductor components, and th...

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Problems solved by technology

[0004] In the prior art, in order to prevent copper metal atoms from diffusing into the dielectric layer, such as titanium nitride (TiN) or tantalum nitride (TaN) is usually used to make the barrier layer, US Patent No. US 6,541,374 B1 is It is mentioned that TiN is used to form the barrier layer, but actually when the barrier layer 190 is deposited, since the deposition direction is approximately perpendicular to the wafer surface, the thickness deposited on the sidewall of the dual damascene structure 10 will be approximately Only one-fifth to one-half of the thickness deposited above the bottom of the hole in the first dielectric layer 160 and the bottom of the trench in the second dielectric layer 180 is likely to cause incomplete sidewall deposition and make the rear dual damascene structure 10 The copper metal atoms formed in the dielectric layer diffuse into the dielectric layer, thereby affecting the electrical properties of the dielectric layer and damaging the entire semiconductor device. Therefore, the barrier layer on the inner wall of the dual damascene structure 10 is completely deposited to prevent the diffusion of copper metal atoms. to the requirement within the dielectric layer

[0005] On the other hand, the resistivity of metal nitride in the prior art is much higher than that of metal materials, so when titanium nitride or tantalum nitride is used as the barrier layer 190 in the dual damascene structure 10, it will make The resistivity between metals in the dual damascene structure 10 is too high to affect the operating speed and power consumption of the semiconductor device, so there is a need to reduce the resistivity of the barrier layer 190 above the bottom of the hole in the first dielectric layer 160

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