Substrate processing method and substrate processing apparatus

Abstract

There is provided a substrate processing method which is capable of lowering the initial cost and the running cost of an apparatus, does not require a wide installation space, does not degrade electrical characteristics such as an interconnect resistance and a leakage current, and is capable of efficiently forming a high-quality alloy film on the surface of a metal region. The substrate processing method including; preparing a substrate having a metal region on a surface thereof, performing a pre-plating treatment by bringing a pretreatment liquid into contact with the surface of the substrate to modify the entire surface thereof, removing the pretreatment liquid remaining on the surface of the substrate in a rinsing treatment, performing an electroless plating process on the surface of the substrate to selectively form an alloy film on the surface of the metal region, and post-cleaning the substrate after the electroless plating process and drying the substrate.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a substrate processing method and a substrate processing apparatus, and more particularly to a substrate processing method and a substrate processing apparatus used for forming, on bottom surfaces and side surfaces or exposed surfaces of embedded interconnects which have been formed by embedding an electrical conductor (interconnect material) such as copper or silver into fine interconnect recesses provided in a surface of a substrate such as a semiconductor wafer, a conductive film having a function to prevent thermal diffusion of the interconnect material into an interlevel dielectric layer or a function to improve adhesiveness between the interconnects and an interlevel dielectric layer or a interlevel cap film (anti-oxidizing film), or a metal alloy film such as a magnetic film covering the interconnects by electroless plating. [0003] 2. Description of the Related Art [0004] As a...

AI Technical Summary

Benefits of technology

[0072] It is thus possible to eliminate the light-excited motion of electrons in devices, interconnects, etc. formed in a device surface of the substrate while the substrate is being processed, preventing damage from being made to the substrate devices.

[0073] According to the present invention, by successively performing processes for forming an alloy film selectively on the surface of the metal region on the surface of the substrate according to electroless plating, the overall apparatus is more compact, does not require a wide installation space, has a lower initial cost and a lower running cost, and can form an alloy film within a shorter processing time, than would be if the processing steps were performed by separate units (processing units). In particular, waiting times or transfer times for the substrate between the processing steps can be adjusted to extremely short times, or it is possible to form a high-quality alloy film while preventing its electrical characteristics from being lowered by successively performing surface cleaning, catalyst imparting, rinsing, and plating processes in a hardly oxidizing atmosphere.

Problems solved by technology

Therefore, at the same time that the pre-cleaning treatment is performed, part of the copper interconnect is damaged (etched), resulting in an increase in the resistance of interconnect.

After the pre-cleaning treatment is performed, when the insulating film is rinsed with pure water after it is treated with the pre-cleaning chemical solution, if the insulating film is exposed to the chemical solution or the rinsing liquid for a long time, then the insulating capability of the insulating film is lowered, possibly resulting in an increase in the leakage current.

If the chemical solution remains on the surface of the substrate after it is treated with the chemical solution, then the within-wafer uniformity of the deposited film is adversely affected.

From an apparatus viewpoint, on the other hand, if the above various processes are performed by respective dedicated units, then not only the number of processing tanks in the respective processes is increased, but also a limitation is imposed on efforts to shorten the time to transfer substrates with a transfer robot.

As a result, not only the apparatus footprint is increased and the processing throughput is lowered, but also process control between the processes is complicated.

In particular, if the substrate is left in an oxygen atmosphere for a long time between the catalyst applying treatment and the rinsing treatment or between the rinsing treatment and the plating process, then the surface state of the substrate is liable to change, and the electrical characteristics of the interconnects on the processed substrate are possibly adversely affected.

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