The roles of N and P type Si(100) substrates in the nucleation and growth of textured diamond films by hot filament chemical vapor deposition

P-Si(100) and n-Si(100) substrates had quite different responses to the sam e process parameters used in the modified four-step diamond growth method, i.e., pretreatment, heating, bias enhanced nucleation (BEN) and bias textur e growth (BTG), which has been developed to grow textured diamond films by hot filament chemical vapor deposition. At the pretreatment step, a bright blue plasma discharge induced the formation of damaged voids randomly distr ibuted on the surfaces of p-Si(100) and n-Si(100). The damaged voids on p-S i(100) are several microns in size and 3 mu m in depth. In contrast, the si ze and depth of the damaged voids on n-Si( 100) are in nanometer scale, app roximately two orders of magnitude lower than those on p-Si( 100). At the B EN step, carburization occurred along with the possibility of diamond nucle ation. Unfacet nuclei of micron scale distributed around the edge of damage d voids all over the p-Si( 100) substrate. In contrast, a great number of s mall nuclei of nanometer scale spread and covered all the damaged voids aro und the outer edge of the n-Si(100) substrate. The continuous textured diam ond film grown on p-Si(100) had better diamond quality than that on n-Si(10 0) at the BTG step. The textured diamond film on p-Si(100) was flat, howeve r, that on n-Si(100) was under stress in convex shape. Ion bombardment at t he BTG step resulted in the enhancement of the growth of textured diamond a nd in the degradation of diamond quality through the formation of amorphous carbon. P-Si( 100) is considered better than n-Si( 100) to be the substrat e for textured diamond deposition. (C) 1999 American Institute of Physics. [S0021-8979(99)04206-1].