TECHNICAL FIELD

Embodiments of the present disclosure generally relate to methods for depositing or forming graphene. Some embodiments of the disclosure relate to methods for forming graphene hard mask films on a dielectric substrate. Some embodiments relate to methods for improving the substrate surface quality or deposition parameters while depositing graphene.

BACKGROUND

Graphene has been attracting tremendous amounts of attention in semiconductor manufacturing as a result of its outstanding optical and electrical properties. Due to its unique 2D honeycomb-shaped lattice and one atomic layer structure, graphene, a monolayer of carbon atoms arranged in a hexagonal lattice, has extraordinary potential for the future of the electronics industry. Graphene is the thinnest material, with a thickness of one carbon atom, about 3.35 angstrom. Therefore, graphene has the highest specific surface area (SSA) recorded among carbon materials. This high SSA provides the promising attribute that graphene is able to store more energy than other carbonaceous materials. In addition, the delocalized electrons in graphene sheets are able to travel at high speeds with intrinsic mobility of about 2-2.5×105cm2/vs; thereby helping to transport current efficiently. Due to its thin thickness and high electron mobility, graphene can be used as a replacement for traditional metal barrier layers in next generation semiconductor devices because the resistance of metal lines gets higher and higher as their thickness and dimensions continue to shrink. Graphene also demonstrates high optical transparency, which can be used in flexible electronics, for example in smart watch applications.

Traditional graphene CVD growth requires high temperature (>1000 C) and metal foils as catalysts. At this high temperature, most materials used in the electronic applications could be damaged. In addition, the metal foils need to be removed after graphene growth. The transfer process is costly, and could damage graphene hard mask films and cause metal contamination as well. For this reason, low temperature growth without using metal catalysts is highly desirable.

Currently, chemical vapor deposition (CVD) with metal catalysts is used to grow graphene films. Although high quality graphene films can be deposited by CVD growth, it requires high growth temperature, typically 800-1000° C. or more. This is not compatible with current integration flows in the semiconductor industry because the metal lines and low k films on device wafers cannot tolerate such high temperatures. In addition, graphene deposited by high temperature CVD also needs to be transferred from the metal foils. The transfer process is costly and can lead to damage of the film, defects in the film, and metal contamination. Therefore high temperature CVD by known methods is neither convenient nor feasible for industrial applications. So, direct growth on arbitrary substrates without the use of metal catalysts at relatively lower temperatures is highly desirable.

Accordingly, there is a need for improved methods of depositing graphene hard mask films.

SUMMARY

One or more embodiments of the disclosure are directed to a method of forming a graphene hard mask film. The method comprises: exposing a substrate to an aromatic precursor in a processing chamber; purging the processing chamber of the aromatic precursor; heating the substrate to a temperature less than 600° C. to polymerize the aromatic precursor and deposit a graphene hard mask film on the substrate; and purging the processing chamber.

Additional embodiments of the disclosure are directed to methods of forming a film. In one or more embodiments, the method comprises: forming a flowable graphene hard mask film on a substrate by exposing the substrate to an aromatic precursor; and exposing the substrate to a plasma.

Further embodiments of the disclosure are directed to a non-transitory computer readable medium including instructions, that, when executed by a controller of a processing chamber, causes the processing chamber to perform operations of: expose a substrate to an aromatic precursor in a processing chamber; purge the processing chamber of the aromatic precursor; heat the substrate to a temperature less than 600° C. to polymerize the aromatic precursor and deposit a graphene hard mask film on the substrate; and purge the processing chamber.

