类金刚石膜的应用及制备

类金刚石膜（DLC）是由无定形碳和金刚石相混合组成的碳材料，由于具有与金刚石膜（DF）相类似的性能－优异的机械特性、电学特性、光学特性、热学和化学特性以及生物相溶性，同时制备方法相对容易实现，因此引起人们极大兴趣，现在已经应用到很多领域。本文将简要介绍类金刚石膜的性能、应用以及制备方法。     

等离子体化学气相沉积类金刚石碳膜的特性及应用

类金刚石（DLC）膜是含有sp^3杂化态的亚稳态非晶碳膜，是具有极高的硬度、化学稳定性和光学透明性的半导体材料。这篇综述介绍了用等离子体化学气相沉积DLC膜的沉积方法、所制备薄膜的特性及应用，最后展望了DLC膜的发展趋势。     

Optimisation of diamond-like carbon films by unbalanced magnetron sputtering for infrared transmission enhancement

Diamond-like carbon (DLC) films have potential applications in infrared transmission enhancement. Reducing or eliminating mechanical stress and optical absorption of DLC is important in such applications because relatively thick films are necessary. In this work, DLC was deposited in an unbalanced magnetron sputtering (UBMS) system. Mechanical and optical properties of the DLC films were analysed. Thick DLC films were deposited which satisfied applications for the infrared windows at 3–5 and 8–10 μm. At optimised conditions, the stress in the DLC films decreased with increasing thickness, approaching 1 GPa. For single side DLC coated silicon substrate, about 69% transmittance was achieved at wavelengths near 5 μm, close to the theoretical value for non-absorbing DLC material. Other properties such as surface roughness, wetting angle, and stability were also studied, which showed that the DLC films produced in the UBMS system were excellent for infrared transmission enhancement applications in tough environments.     

Optical and mechanical properties of diamond like carbon films deposited by microwave ECR plasma CVD

Diamond like carbon (DLC) films were deposited on Si (111) substrates by microwave electron cyclotron resonance (ECR) plasma chemical vapour deposition (CVD) process using plasma of argon and methane gases. During deposition, a d.c. self-bias was applied to the substrates by application of 13·56 MHz rf power. DLC films deposited at three different bias voltages (−60 V, −100 V and −150 V) were characterized by FTIR, Raman spectroscopy and spectroscopic ellipsometry to study the variation in the bonding and optical properties of the deposited coatings with process parameters. The mechanical properties such as hardness and elastic modulus were measured by load depth sensing indentation technique. The DLC film deposited at −100 V bias exhibit high hardness (∼ 19 GPa), high elastic modulus (∼ 160 GPa) and high refractive index (∼ 2·16–2·26) as compared to films deposited at −60 V and −150 V substrate bias. This study clearly shows the significance of substrate bias in controlling the optical and mechanical properties of DLC films.     

Surface adsorption and wetting properties of amorphous diamond-like carbon thin films for biomedical applications

Diamond-like carbon (DLC) thin films have unique properties for biological and medical applications due to their excellent bio-compatibility, chemical inertness, and superior mechanical properties. It is important to understand the surface properties of DLC thin films for these applications. In this work, we showed that after DLC deposition, NiTi surfaces became much smoother by choosing suitable deposition conditions. Adsorption and wetting properties of DLC films were studied. The adsorption properties of DLC films were unusual in that a hysteresis was found in the adsorption/desorption isotherms, which cannot be interpreted using the conventional theory of capillary condensation in pores. The model proposed in this work for this unusual hysteresis characteristic is that the hysteresis results from the non-wetting property of DLC surfaces in the nano-scale. The nano-sized droplets formed on the DLC surfaces may require significantly higher energy to evaporate than the formation energy. Argon plasma treatment resulted in a small decrease of the contact angles. After oxygen plasma treatment, the wetting contact angles reduced significantly due to the increase of carbon-oxygen sites on the surfaces, suggesting that the low concentration of carbon-oxygen sites on the surfaces of DLC films contributed to the adsorption hysteresis observed in this work.     

Deposition of diamond like carbon (DLC) and C-N films using ion beam assisted deposition (IBAD) technique and evaluation of their properties

Diamond like carbon films and C-N films were prepared using ion beam assisted deposition technique (IBAD). Tribological properties were studied by subjecting DLC coated films to the accelerated wear tests. These tests indicated a significant improvement in the mechanical surface properties of glass by DLC coating. Better wear features were obtained for thinner DLC coating as compared to the thicker ones. We also studied the optical properties and obtained a band gap of 1·4 eV for these films. An attempt was made to prepare C₃N₄ films by using IBAD. We observed variation in the nitrogen incorporation in the film with the substrate temperature.     

Preparation of wide range refractive index diamond-like carbon films by means of plasma-enhanced chemical vapor deposition

Plasma-enhanced chemical vapor deposition technology has been elaborated for obtaining diamond-like carbon (DLC) coatings of a wide range of properties. Alternative and direct bias voltages have been applied on the substrate, and refractive index dependencies upon various deposition technological parameters have been investigated. The frequency of the bias voltage has been varied in the region of 150-450 kHz. The maximum refractive index range that has been achieved is 1.46-3.2. Thin DLC films have been prepared on crystalline silicon substrates. Because of the wide range of physical, optical, and mechanical properties of the obtained films, they can successfully be applied in different fields of nano-optics.     

Hochleistungsplasmen zur Synthese diamantähnlicher Kohlenstoffschichten

HPPMS high‐performance plasmas for the deposition of diamond‐like carbon coatings Diamond‐like carbon (DLC) coatings Diamond‐like carbon (DLC) coatings can be used in many different applications, due to their adjustable properties like hardness as wear reduction. Regarding to the synthesis of these coatings, research is upon the High Power Pulsed/Impulse Magnetron Sputtering (HPPMS/HiPIMS), which in contrast to conventional processes like the Pulsed Laser Deposition (PLD) provides smooth coatings and therefore less postprocessing. Previous to the coating deposition in‐situ plasma analysis can be utilized to identify the process parameters. The aim relevantof this work was to identify process parameters which enable to generate a high amount and energy of carbon ions, which are required to synthesize hard DLC coatings. Regarding to the carbon ionization the promising process parameters mixture and pressure of the process gas as well as the HPPMS pulse parameters were varied. Finally, process parameters for the DLC coating deposition could be derived from these investigations.     

Evolution of optical properties with deposition time of silicon nitride and diamond-like carbon films deposited by radio-frequency plasma-enhanced chemical vapor deposition method

The paper presents investigations of the optical properties of thin high-refractive-index silicon nitride (SiN_x) and diamond-like carbon (DLC) films deposited by the radio-frequency plasma-enhanced chemical vapor deposition method for applications in tuning the functional properties of optical devices working in the infrared spectral range, e.g., optical sensors, filters or resonators. The deposition technique offers the ability to control the film's optical properties and thickness on the nanometer scale. We obtained thin, high-refractive-index films of both types at deposition temperatures below 350 °C, which is acceptable under the thermal budget of most optical devices. In the case of SiN_x films, it was found that for short deposition processes (up to 5 min long) the refractive index of the film increases in parallel with its thickness (up to 50 nm), while for longer processes the refractive index becomes almost constant. For DLC films, the effect of refractive index increase was observed up to 220 nm in film thickness.     

Some electrical properties of diamond-like carbon thin films

Diamond-like carbon (DLC) belongs to very interesting materials used for a number of practical applications. It was noted that the electrical properties of DLC films obtained by RF PCVD discharge depend substantially on the deposition conditions. The results and discussion of the electrical properties of DLC films and DLC/Si heterostructures is presented. The electrical conductivity results are explained in terms of hopping mechanism. The relation between charge transport, structure of the energy gap and the deposition conditions is discussed.