Boettger, E.E.BoettgerBluhm, A.A.BluhmJiang, X.X.JiangSchaefer, L.L.Schaefer2022-03-082022-03-081995https://publica.fraunhofer.de/handle/publica/303274The invention relates to a process for the production of polycrystalline diamond layers on substrates with basically known process gases such as hydrogen, methane, oxygen or similar, by means of a CVD process, whereby the growth phase of the diamond layer is performed in the presence of an additional process gas which consists of N<-2 and/or nitrogen-containing gas mixtures such as air or N<-2 /H<-2 and/or nitrogen-hydrogen, nitrogen-oxygen or nitrogen-halogen compounds and/or mixtures of the nitrogen compounds described above with gases such as oxygen or hydrogen, whereby nitrogen is part of the process gas with 0.005 to 1 percent by volume or there is a relation of nitrogen to carbon (N/C ratio) of 0.001 to 0.2 of the total process gas.de608667patent1993-4331701