NOVEL MOCVD PROCESS FOR THE LOW TEMPERATURE DEPOSITION OF THE CHROMIUM NITRIDE PHASES

摘要

An MOCVD route for the low temperature deposition of each individual phase of the Cr-N system has been investigated. The chromium nitride coatings were deposited under low pressure on steel and silicon substrates at temperature as low as 723 K using bis(benzene)chromium as Cr source under NH_3 ambient and in presence of C_6Cl_6 vapor. The carbon contamination of the layers is very low and limited to a few atomic percent. The nature of the deposited phases depends on the NH_3:Cr(C_6H)6)_2 mole fraction ratio. Single-phase CrN and dual-phase CrN+Cr_2N coatings have been deposited by this triple-source process. Preliminary mechanical properties of the layers are reported and discussed in relation with their composition and microstructure.