Growth and morphological studies of hydrogenated diamond like carbon films deposited by radio frequency plasma enhanced chemical vapour deposition

Abstract

Diamond-like carbon (DLC) is a name attributed to a variety of amorphous carbon materials, containing hydrogen in various range of atm.% of hydrogen, some containing up to about 50 atm.% hydrogen (a-C:H) and some other contains less than 1 atm.% (a-C ). The DLC term is commonly used to designate the hydrogenated form of diamond-like carbon (a-C:H), while the ta-C (tetrahedral amorphous carbon) term is used to designate the non-hydrogenated carbon (a-C), containing high fractions of sp3 hybridized carbon. An accurate control of the surface morphology and roughness of plasma deposited thin films is of crucial importance in many technological applications. The surface growth dynamics is a characteristic of both the deposition technique and process conditions applied during the film growth. Therefore, the morphological study can reveal the information about uniform and long range coating mechanisms operating for a given system as functions of deposition parameters. In the present research, the sequential variation of surface morphology of capacitively coupled RF-PECVD grown DLC films on silicon (100) substrate have been studied under three phases namely, during: growth, variation in the major RF-PECVD parameters (plasma pressure and deposition temperature) and post deposition treatment (annealing at high temperature). CH4 and Ar were used as the precursor gases to grow DLC film. This thesis consist of six chapters, the first chapter gives the brief introduction about the classification of amorphous carbon and also discusses the basic structure, properties and some application of the DLC films. Various deposition techniques ranging from IBD to RF-PECVD have been explained in brief. An overview of the development in growth mechanism of DLC films in RF-PECVD has been discussed with historical background in this chapter. Finally, an outline of the work undertaken as research is discussed. The second chapter divides into two sections.