顶栅石墨烯离子敏场效应管的表征及其初步应用  

Characterization and preliminary application of top-gated graphene ion-sensitive field effect transistors

作　　者：吴春艳[1,2] 杜晓薇[2] 周麟[2] 蔡奇[2] 金妍[2] 唐琳[2] 张菡阁 胡国辉[1] 金庆辉[2] 

机构地区：[1]上海大学,上海市应用数学和力学研究所,上海200072 [2]中国科学院上海微系统与信息技术研究所,传感技术联合国家重点实验室,上海200050

出　　处：《物理学报》2016年第8期60-67,共8页Acta Physica Sinica

基　　金：国家高技术研究发展计划(批准号:2014AA06A506);国家自然科学基金(批准号:61501441;61401442);中国科学院中德国际合作伙伴团队项目(批准号:GJHZ 1306);上海市科委项目(批准号:14ZR1447300,15220721700);上海市教委基础研究重点项目(批准号:14ZZ095)资助的课题~~

摘　　要：传统的液栅型石墨烯场效应管虽然灵敏度高,但是石墨烯沟道极易被污染,致使器件的稳定性减小,不能被重复利用.为此,我们设计制造了一种顶栅石墨烯离子敏场效应管,以化学气相沉积生长的石墨烯为沟道,通过原子层沉积在石墨烯表面沉积绝缘层Hf O_2/Al_2O_3,其中Al_2O_3作为敏感膜,Hf O_2/Al_2O_3作为石墨烯及电极的保护膜.经过一系列的电学表征和测试发现,相较于液栅型石墨烯场效应管,顶栅石墨烯场效应管具有更高的信噪比、更好的稳定性.为了利用顶栅石墨烯进行生物分子的检测,我们将单链DNA修饰在Al_2O_3表面,成功检测到了修饰DNA前后的信号差异,并结合荧光修饰的表征验证了顶栅石墨烯场效应管用于生物传感器的可行性.Graphene, a 2-dimensional material, has received increasing attention due to its unique physicochemical properties（high surface area, excellent conductivity, and high mechanical strength）. Field-effect transistor is shown to be a very promising candidate for electrically detecting chemical and biological species. Most of the reports on graphene field-effect transistors show that solution-gated graphene field effect transistors have been used so far. Although the traditional solution-gated graphene field effect transistor has high sensitivity, but the graphene channel is contaminated easily. The stability of the device is reduced so that the device cannot be reused. Only very recently, has the top-gated graphene,which is potentially used for p H sensors, been reported. In the top-gated graphene the dielectrics is deposited at the top of graphene. However, the sensitivity is lower than other sensors. To improve the properties, we design and fabricate a top-gated graphene ion-sensitive field effect transistor by using large-area graphene synthesized by chemical vapor deposition. At the top of graphene, Hf O2/Al2O3 thin film is deposited by atomic layer deposition. The Al2O3 film plays a role of sensitive membrane, and the Hf O2/Al2O3 thin film protects the graphene from contamination of the solution. After depositing the top-gate, because of the shield of the insulation, the boundary between the graphene and the substrate is not clear. And the Raman spectrum indicates the presence of a defective top layer accompanied by an increase in the Raman D peak. After a series of electrical characterizations, compared with solution-gated graphene field effect transistor which directly contacts the graphene channel with the solution, the top-gated graphene ion-sensitive field effect transistor has a high resistance. This increase relative to uncovered grapheme, is attributed to the participation of the top π-orbitals in van der Waals bonds to the insulation. The graphene π-orbitals contributing to van der Waals bonds hav

关 键 词：石墨烯 场效应管 HfO2/Al2O3 水基-原子层沉积 

分 类 号：O613.71[理学—无机化学]