Study On CMP Slurry Of CVD Diamond Film

Diamond has excellent mechanical properties, thermodynamic properties, optical properties, acoustic properties, semiconductor performance and chemical inertness. As a full range of multi-functional material in many fields it has very broad application prospects. Although the advent of CVD diamond film has eased the matter of natural diamond's few reserves and valuableness, its poor surface quality makes it difficult to be used directly in many cases. So the diamond film's polishing has become one of the key technologies to expand its application.In the past nearly two decades, a large number of scholars and engineers have in-depth studied on the polishing diamond films, researched various polishing methods, established a wide range of theoretical models and yielded fruitful results of research. However, these methods such as: electrical discharge polishing thermo-chemical polishing, can achieve the polished surface roughness remaining in the sub-micron. And they are easy to cause damage layers on the diamond films" surface. It is lack of an ultra-precision and low-injury polishing method, so the scholars CVD have never stopped probing the diamond films' polishing technicses. There are emerging plenty of new theories and methods.In this paper, a CMP method has been studied, the main contents and conclusions of the study are as follows:(1) According to the oxidation-reduction potential, 10 kinds of antioxidants are used to polishing experiments. The effects of different oxidizer on the diamond films' materials removal and surface roughness have shown that potassium permanganate as the oxidizer is the best choice.(2) Some chemical reagents such as sulfuric acid, phosphoric acid, ferric chloride as the additive have been experimentized. Phosphoric acid has been as the additive for its better material removal rate and surface roughness. And the additive concentration is optimized, the experiment found that the best concentration is phosphoric acid phosphate: deionized water = 115ml: 35ml at the best polishing.(3) After the oxidizer and additives has been determined, the abrasive hardness and particle size are optimized, the results show that: in the rough machining process, 10μm diamond used as abrasive, in the finish machining process, 2μm boron carbide used as abrasive can get the best effect. (4) The lap material is optimized, and the results show that: in the rough machining process it should use the wear-resistant boron carbide dish, and in the finish machining process it should use glass dish which has moderate hardness, the ability of the material contained in.(5) Finally, the main technical parameters has been through the studied by Orthogonal experiment. The best technical parameters which have been optimized are that: the pressure is 0.35MPa, the speed of lap is 50r/min, the speed of up disk is 70r/min, the temperature is 50℃.(6) There is a good surface quality and no metamorphic layer deterionration or other impurities after polished by optimization of process.