ICP etching of polycrystalline diamonds: Fabrication of diamond nano-tips for AFM cantilevers

Diamond nano-tips for measurements of living-cell activities have been fabricated from polycrystalline diamond/Si substrates using an inductively coupled plasma reactive ion etching (ICP-RIE) system. Mixtures of O2 and CF4 gas in a plasma was used as etching atmosphere. The etching properties of polycrystalline diamond film have been characterized. During etching of polycrystalline diamond, unintentional nano whiskers were formed due to the inhomogeneity of chemical bonds at grain boundaries. Finally, nano-tips longer than 10 μm and with an apex radius below 50 nm without nano whiskers have been realized.