MEMS fabrication of high aspect ratio track-following microactuator for hard disk drive using silicon on insulator

We have achieved a high aspect ratio track-following microactuator (TFMA) which is capable of driving 2 /spl mu/g magnetic head for hard disk drive (HDD). It was fabricated on silicon on insulator (SOI) wafer with 20 /spl mu/m thick active silicon and 2 /spl mu/m thick thermally grown oxide and piggyback electrostatic principle was used for driving TFMA. The first vibration mode frequency of TFMA was 18.5 kHz which is enough for a recording density of higher than 10 Gb/in/sup 2/. Its displacement was 1.4 /spl mu/m when 15 V DC bias plus 15 V AC sinusoidal driving input was applied and its electrostatic force was 50 /spl mu/N when input voltage was 30 V.