Due to its combination of unique physical properties diamond is an outstanding H2, CH4 material. Besides its unrivaled hardness diamond exhibits ultrabroadband transparancy ranging from deep uv to the microwave regime, and a thermal conductivity at room temperature which is higher than that of any other material Microwave-Plasma The excellent mechanical. thermal optical and insulating properties of diamond became accessible through the =700-900°C advent of low pressure Chemical Vapour Deposition(CvD) techniques which allow diamond in the form of extended films and free-standing wafers to be fabricated The fundamental problem of diamond synthesis is the allotropic nature of carbon Under ordinary conditions graphite, not diamond, is the thermodynamically stable crystalline phase of carbon. Hence, the main requirement of diamond CVD is to deposit carbon and simultaneously suppress the formation of graphitic sp -bonds This can be realized by establishing high concentrations of non-diamond carbon etchants such as atomic hydrogen. Usually, those conditions are achieved by admixing large amounts of hydrogen to the process gas and by activating the gas either thermally or by a plasmaThe fundamental problem of diamond synthesis is the allotropic nature of carbon. Under ordinary conditions graphite, not diamond, is the thermodynamically stable crystalline phase of carbon. Hence, the main requirement of diamond CVD is to deposit carbon and simultaneously suppress the formation of graphitic sp2 -bonds. This can be realized by establishing high concentrations of non-diamond carbon etchants such as atomic hydrogen. Usually, those conditions are achieved by admixing large amounts of hydrogen to the process gas and by activating the gas either thermally or by a plasma. Due to its combination of unique physical properties diamond is an outstanding material. Besides its unrivaled hardness diamond exhibits ultrabroadband transparancy ranging from deep UV to the microwave regime, and a thermal conductivity at room temperature which is higher than that of any other material. The excellent mechanical, thermal, optical and insulating properties of diamond became accessible through the advent of low pressure Chemical Vapour Deposition (CVD) techniques which allow diamond in the form of extended films and free-standing wafers to be fabricated