Diamond films on 1 x 1 cm(2\) Si (100) substrates were synthesized by microwave plasma chemical vapor deposition (MWCVD) using mixture of methane and hydrogen gases. Bias-enhanced nucleation method was used to avoid any mechanical pretreatments. Distribution of deposited diamond crystallites in terms of density, size, and morphology has been significantly improved over all the Si substrate surface area by using a novel designed Mo anode. Films were characterized from the center to the edges of substrates using scanning electron microscopy, transmission electron microscope, and Raman analysis. The results also show that uniform diamond films can be obtained by short bias nucleation period using a dome-shaped Mo anode. The diamond crystallites were directly deposited on Si substrate. Using 2% CH4 in the growth stage, high quality diamond films in the < 100 > texture can be obtained with relatively smooth surface. (c) 2005 Elsevier B.V. All rights reserved.