近年来微机电系统（MEMS）在传统和高新技术领域都得到广泛的应用，但是尺寸效应引起的摩擦磨损问题已经成为MEMS失效的关键因素。原子层沉积（ALD）由于其优异的薄膜覆盖率非常适合应用在MEMS领域。过渡金属硫化物二硫化钨（WS2）具有非常优良的润滑性能，但是目前还没有成熟的ALD工艺。本文主要研究了WS2薄膜的ALD制备，摩擦学特性及其在MEMS减摩中的应用。首先以W(CO)6和H2S为前驱体摸索出了WS2的ALD工艺，分别在Si基底和ZnS过渡层上制备出了WS2薄膜，并研究了WS2薄膜生长过程中的晶格取向，生长模式和ZnS过渡层的影响。结果表明WS2薄膜的ALD沉积速率为0.36 nm/周期，晶格主要为（002）和（101）取向，生长模式为初始阶段基面平行于基底，之后基面开始随机取向。并且ZnS过渡层相比Si基底能够吸附更多的W元素和S元素，提高WS2薄膜的致密性，进而促进WS2薄膜的生长。然后分别研究了WS2薄膜在宏观和微观下的摩擦特性，宏观下验证了薄膜的润滑机理，并分析测试了Si基底和ZnS过渡层对摩擦特性的影响。结果表明当载荷由0.5 N增加到2 N时，Si基底上的WS2薄膜摩擦系数由0.109减小到0.076，而ZnS过渡层上的WS2薄膜的摩擦系数由0.089减小到0.051。润滑机理为在惰性气体氛围下，WS2薄膜会在对磨面生成一层转移膜，同时在摩擦接触区晶粒会重新取向生成一层极薄的（002）基面层，由于对磨面上的转移膜与（002）基面层之间的剪切阻力非常小，因此摩擦系数非常低。纳米划痕实验表明ZnS过渡层可以提高WS2薄膜与基底的结合力，进而增加WS2薄膜的磨损寿命。微观下利用AFM分别测量了WS2薄膜的粘附力和犁沟力，研究了沉积周期和薄膜粗糙度对摩擦特性的影响。结果表明WS2薄膜可以大幅度地减小Si表面的粘附力，并且薄膜的粗糙度越大，AFM探针与薄膜的实际接触面积越小，测得的粘附力就越小。此外随着沉积周期的增加，WS2薄膜在两种沉积基底上的粗糙度基本一致，但是ZnS过渡层上的WS2薄膜的质量更好，因此表现出了更低的粘附力（20 nN）。最后测试了WS2薄膜在MEMS微摩擦器件的应用效果，结果表明WS2薄膜能减小MEMS器件的粘附力和静摩擦力。MEMS微摩擦器件在沉积WS2薄膜后，摩擦系数从0.52±0.11减小为0.21±0.06。因此针对MEMS中的摩擦磨损问题，利用ALD工艺制备WS2润滑薄膜提供了一种新的解决方法。

In recent years, micro-electromechanical systems (MEMS) have been widely used in both traditional and high-tech fields. However, the friction and wear problems induced by size effect have been becoming major concerns of silicon based MEMS. Due to precise thickness control and excellent step coverage, Atomic layer deposition (ALD) is ideally suited for MEMS devices with complex 3-dimensional microstructure. Transition metal dichalcogenides tungsten disulfide (WS2) is very famous for its excellent lubrication behavior, but up to now, there is still no mature ALD deposition recipe. In this study, the synthesis by ALD, tribological properties of WS2 films and their application in MEMS were systematic investigated.To begin with, a new direct atomic layer deposition method to grow lubricant WS2 films was found. The WS2 films were deposited on Si substrates and ZnS film coated Si substrates using tungsten hexacarbonyl (W(CO)6) and hydrogen sulfide (H2S) as precursors, and during the WS2 deposition, the influence of lattice orientation, growth mode and impact of the ZnS transition layer were studied. It is found the growth rate of the WS2 films is 0.36 nm/cycle, and the WS2 grains are (002) and (101) orientated. The growth mode is revealed that in the initial few layers of the WS2 films, the basal plane is (002) orientated. In the bulk film, the basal plane is randomly orientated. In addition, the ZnS transition layer can promote the growth of WS2 films because the ZnS transition layer can absorb more W element and S element than the Si substrate.Next, the macro-tribological and micro-tribological characteristics of the WS2 films were studied. The influence of Si substrate and ZnS transition layer on the tribological characteristics of the films was investigated using UMT3 sliding friction tester, and the lubrication mechanism of the WS2 films was verified. It is found that as the normal loads increase from 0.5 N to 2 N, the friction coefficients of theWS2 films on Si substrates decrease from 0.109 to 0.076, the friction coefficients of theWS2 films on ZnS coated Si substrates decrease from 0.089 to 0.051. The lubrication mechanism of low friction consists of three points, firstly the environment is dry inert gas or ultrahigh vacuum, and secondly a transfer film is formed on the counterface, and thirdly an extremely thin (002) basal planes layer is regenerated at the top of the wear track. Besides, as the ZnS transition layer can enhance the adhesion strength between the WS2 film and the substrate, the WS2 films on ZnS coated Si substrates show better tribological performance with longer wear life. The adhesion and furrow force of WS2 films were measured by AFM, and the effects of deposition cycles and film roughness on the tribological characteristics of the WS2 films were investigated. It is found that WS2 film can greatly reduce the adhesion of Si surface, and the rougher the surface, the smaller the actual contact area between the probe and the film, then the measured adhesion force becomes smaller. Furthermore, the roughness of WS2 film on the two kinds of deposition substrates is basically the same with the increasing of the deposition cycles, but the WS2 films grown on ZnS coated Si substrates which possess better film quality exhibit lower adhesion force (20 nN). Finally, the WS2 films were applied to MEMS micro-friction devices to verify the anti-friction performance. It is found that the WS2 films can reduce the adhesion and friction force of the MEMS devices. The friction coefficients decrease from 0.52 ± 0.11 to 0.21 ± 0.06 after the deposition of WS2 thin films. Therefore, the ALD-WS2 lubricating films provide a new solution to the friction and wear problems of silicon based MEMS.