Diamond deposition in a DC-arc Jet CVD system: investigations of the effects of nitrogen addition

Studies of the chemical vapour deposition of diamond films at growth rates > 100 mum h(-1) with a 10-kW DC-arc jet system are described. Additions of small amounts of N-2 to the standard CH4/H-2/Ar feedstock gas results in st rong CN(B --> X) emission, and quenches C-2(d --> a) and H-alpha emissions from the plasma. Species selective, spatially resolved optical emission mea surements have enabled derivation of the longitudinal and lateral variation of emitting C-2, CN radicals and H (n = 3) atoms within the plasma jet. Sc anning electron microscopy and laser Raman analyses indicate that N-2 addit ions also degrade both the growth rate and quality of the deposited diamond film; the latter technique also provides some evidence for nitrogen inclus ion within the films. (C) 2001 Elsevier Science B.V. All rights reserved.