Effect of H₂on Plasma Enhanced Chemical Vapor Deposition of Graphene on HfO₂Substrate AITranslate

8黄笑乐,铁渊,吴宇浩,朱正荣,邓磊,车得福.温度及水洗预处理对生物质氧气-水蒸气气化特性的影响[J].中南大学学报(自然科学版),2023,54(10):4094-4102.

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Chinese Library Classification Number:TG146.21[金属学及工艺—金属材料]

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HfO₂thin film and graphene are the main materials used in the fabrication of graphene field-effect transistors.Employing plasma enhanced chemical vapor deposition(PECVD)for the in-situ growth of graphene on HfO₂substrate represents a highly promising method for graphene synthesis,which mitigates the impact of the graphene transfer process on graphene quality to consequently improve the performance of graphene field-effect transistors.HfO₂thin film samples with a thickness of 100 nm were deposited on heavily doped single-side polished silicon substrates using vacuum electron beam evaporation at temperatures of 50℃,150℃and 250℃.Subsequently,the HfO₂thin film with the best quality was used as the substrate for the growth of graphene.Graphene thin films were synthesized in-situ by PECVD at a tempe-rature of 600℃and CH_4 flow rate of 4 sccm with varying H₂flow rates(0 sccm,5 sccm,10 sccm,15 sccm and 20 sccm).The results indicate that the HfO₂thin film evaporated at 150℃exhibits the lowest roughness,smoothest surface,and optimal dielectric properties.Graphene thin films with few layers can be obtained at the H₂flow rate of 10 sccm with minimal defects,smooth surface,and good continuity.Analysis of the growth mechanism of graphene on the HfO₂substrate reveals that the low surface energy of HfO₂substrate hinders the adsorption of carbon species onto the substrate,making it challenging for graphene to grow.However,the appropriate involvement of H₂effectively reduces the activation energy for CH₄decomposition,facilitating CH_4 cleavage and favoring the growth of large-area continuous graphene thin films.