Transmission electron microscopy sample preparation method capable of detecting Damascus seed crystal layer and barrier layer

Abstract

The invention discloses a transmission electron microscopy sample preparation method capable of detecting a Damascus seed crystal layer and a barrier layer, which includes the following steps: a diffusion barrier layer A and a seed crystal layer A are sequentially deposited again on a Damascus structure on which the diffusion barrier layer and the seed crystal layer are already deposited according to the standard Damascus process; copper is filled in the Damascus structure, and the copper filled in the Damascus structure plays the supporting role in sample preparation to prevent the deformation of a sample; the Damascus structure is cut into the sample; and transmission electron microscopy is used for detecting the thicknesses of the barrier layers and the seed crystal layers and the deposit coverage topography. Since the transmission electron microscopy sample preparation method utilizes the copper to fill the Damascus structure, the surface of the seed crystal layers can be prevented from being injured by the environment and sample preparation before transmission electron microscopy observation, the copper plays the supporting role in the focused ion beam cutting process, and therefore can prevent the deformation of the Damascus structure caused by sample preparation, and a TEM (transmission electron microscopy) picture can truly reflect the thicknesses of the barrier layers and the seed crystal layers and the deposit coverage topography at the same time.

Description

technical field [0001] The present invention generally relates to the field of semiconductor manufacturing copper interconnection, more precisely, the present invention relates to a transmission electron microscope sample preparation method that can simultaneously detect the thickness of the seed layer and barrier layer and the deposition coverage morphology in the damascene copper interconnection process. Background technique [0002] As the size of CMOS transistors continues to shrink to the sub-micron level, as predicted by Moore's Law, the number of transistors in high-efficiency, high-density integrated circuits rises to tens of millions. The signal integration of these huge number of active components requires more than eight layers of high-density metal wiring. However, the resistance and parasitic capacitance brought by these metal interconnections have become the main factors that limit the speed of this efficient integrated circuit. Driven by this factor, the semic...

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Problems solved by technology

This can protect the seed layer from surface damage caused by the environment and sample preparation before TEM observation, but it is easy to cause deformation of the Damascene structure, and cannot accurately detect the thickness and coverage morphology of the barrier layer and seed layer

Another method is to directly fill the damascene structure with metal copper 03 after the deposition of the diffusion barrier layer 00 and the seed layer 01, such as figure 2 As shown, the filled metal copper 03 supports the Damascus structure and can reduce the deformation of the sample. However, since TEM cannot distinguish the interface position of the copper seed layer and the electroplated copper, this method cannot detect the thickness and coverage of the seed layer. Appearance, only suitable for detection of diffusion barrier layer

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