Microwave plasma chemical vapor deposition (MPCVD) system with microwave frequency 2.45 GHz was used for exciting mixed reaction gases of methane and hydrogen to produce plasma. The p-type (1 0 0) silicon substrate surface was put to contact with plasma to induce plasma sheath potential drop. It introduces an electric field to accelerate positive and lighter hydrogen ions (H+) to etch out sp(2) clusters and amorphous carbons anisotropically. Besides, high-energy ions, hydrocarbon species and hydrogen atoms (H) are diffused to etch out sp(2) clusters and amorphous carbons isotropically. Without externally applying negative bias, nano-tip diamond-like carbon (DLC) film with a few nano-size diamonds and many sp(3) bonding was successfully deposited under the competition of etching and deposition. SEM study shows that the density of DLC nano-tips is up to 20 x 10(8) cm(-2). Its length, bottom diameter and top diameter are about 1.5-2 mum, 300-400 mn, and 20-30 nm, respectively. The deposited film was analyzed by energy dispersion spectrometer (EDX). The result shows that there is no transition metal incorporated in the film. This suggests that the DLC nano-tip growing mechanism is not similar to general growing mechanism of carbon nanotubes. X-ray diffraction spectrometer (XRD) was applied to confirm that a few nano-size diamonds are contained in the film. Finally, Raman spectrometer and Auger electron spectrometer (AES) were used to confirm that a larger amount of sp(3) bonding is incorporated in the film.