Creation of individual holes in SiO/sub 2/ on Si by swift heavy ion bombardment followed by wet and dry etching

It has been known that swift heavy ion bombardment could create latent tracks in amorphous SiO/sub 2/ (a-SiO/sub 2/) which turned into a visible hole by etching. Goal of the present examination is to control the hole contour with various etching methods. It was found that individual conic holes could be obtained on bombarded SiO/sub 2/ by wet etching. In contrast, columnar holes could be created on bombarded SiO/sub 2/ by the hybrid etching, which implied a wet etching with 48% HF followed by RIE with CHF/sub 3/. No holes have been observed on the bombarded SiO/sub 2/ followed by the RIE only.