Parylene N (CAS No. 1633-22-3), a polymer of p-xylene, is a new conformal coating material. Parylene N can be meteorologically deposited under vacuum, and active small molecules "grow" a fully conformable polymer film coating on the substrate surface, which has performance advantages that other coatings cannot match. Parylene N powder can be applied to surfaces of various shapes, including sharp edges, cracks and inner surfaces. It is often used as a surface coating for electronic components and is widely used in semiconductor optoelectronic devices and other fields.

Chen Xu and others from Beijing University of Technology used Parylene N film as a carbon source to directly grow graphene on the silicon surface to prepare a high-efficiency graphene-silicon Schottky junction detector, which provides a new silicon The preparation method of the singular junction detector is helpful to promote its application in the field of visible light and near infrared light detection.

They deposited a parylene N film on the surface of the silicon substrate, and the surface of the parylene N film is etched by an argon plasma, and a cross-linking reaction occurs on the surface of the parylene film during the etching process. The reaction between the relining molecules and the more stable molecules (body molecules) which are crosslinked to form a network structure. The cross-linking reaction only occurs in a thin layer on the surface of the parylene N film. The cross-linked parylene N film can remain stable at higher temperatures without decomposition.  After that, it is rapidly annealed at a high temperature (1100 ° C), and the surface-crosslinked parylene N thin film layer 107 will graphitize the graphene at a high temperature, and the parylene N below the cross-link layer 107 will reach 650 at a temperature. After °C or more, it will decompose and vaporize.

Next, the graphene pattern is etched, and the graphene is etched with an oxygen plasma using a photoresist as a mask to form a graphene-silicon Schottky junction window. Finally, the electrode pattern is lithographically formed, and metal electrodes are made by sputtering or evaporation on the top of the graphene and the back of the substrate, and finally a silicon Schottky junction detector using Parylene N directly growing graphene.

This method uses Parylene N to directly grow graphene without transferring graphene during the process, which not only greatly simplifies the process of the device and improves the production efficiency, but also has little pollution, and the contact between graphene and silicon is better Consistency is better, suitable for batch growth.