Control of diamond micro-tip geometry for field emitter

Arrays of cone-shaped diamond tip can be fabricated using conventional dry etching using silicon oxide dots as an etch-resistant mask. In this work, w e have investigated how the size of the oxide mask dots influences the shap e of the diamond cone tips. Silicon oxide dots (2 mum in diameter, 300 x 30 0 array) were patterned on a polycrystalline diamond film. The thickness of the oxide mask was chosen to be 400 and 800 nm. Under the given etching co ndition the 800-nm thick mask resulted in tips with better aspect ratio. Th is suggested that the longer etching time for a thicker mask helped sharpen ing the diamond tips. (C) 2000 Elsevier Science B.V. All rights reserved.