退火对不同金属薄膜上的BN/MoS_(2)异质结构形貌、结构和电性能的影响

Effect of annealing on morphology,structure and electrical properties of BN/MoS_(2) heterostructures on different metal films

以过渡金属硫化物、氮化硼等二维层状材料为基础,研究了一种简单可靠的集成电路制造方法。在这项工作中,采用射频磁控溅射在室温下逐层制备了M/BN/MoS_(2)(M=Al、Ti、Mo和Ag)纳米薄膜,其中BN/MoS_(2)为未发生化学反应的异质结构,然后在500℃进行退火。结果表明:所制备的金属(Al、Ti、Mo和Ag)、BN和MoS_(2)薄膜均匀连续,特别是BN/MoS_(2)异质结构界面清晰、结合紧密。退火后,顶层MoS_(2)薄膜颗粒大小、粗糙度和结晶性显著提高,且杂质减少甚至消失,其中Ag/BN膜基底上MoS_(2)薄膜结晶性最好,且出现了较大的片层状形态。电性能测试显示金属/BN和BN/MoS_(2)异质结构界面的肖特基势垒使得样品的I-V特性曲线呈明显的非线性。Ti基由于退火后氧化,电阻率最大,Mo基功函数最大,电阻率其次,Ag基功函数相对较低所以电阻率较低,而Al则由于低的功函数、结构匹配及载流子浓度等因素导致其电阻率最低。

A simple and reliable integrated circuit manufacturing method was studied based on two-dimensional layered materials such as transition metal sulfides and boron nitride(BN).In this work,M/BN/MoS_(2)(M=Al,Ti,Mo and Ag)nano films were prepared layer by layer at room temperature using radio frequency magnetron sputtering,wherein the BN/MoS_(2) was a heterogeneous structure without chemical reaction,and then annealed at 500℃.The results show that the prepared metal(Al,Ti,Mo and Ag),BN and MoS_(2) thin films are uniform and continuous,especially the BN/MoS_(2) heterostructure interface is clear and tightly bonded.After annealing,the particle size,roughness and crystallinity of the top layer MoS_(2) film are significantly improved,and the impurities are reduced or even disappeared.Among them,the MoS_(2) film on the Ag/BN film substrate has the best crystallinity and exhibits a large lamellar morphology.The electrical performance tests show that the Schottky barrier at the interface of the metal/BN and BN/MoS_(2) heterostructures results in a significant nonlinearity in the I-V characteristic curve of the samples.Due to oxidation after annealing,Ti has the highest resistivity,while Mo has the highest work function and a slightly lower resistivity than Ti.Ag has a relatively low work function,and a lower resistivity than Mo,while Al has the lowest resistivity due to the factors such as low work function,structural matching and high carrier concentration.