High-sensitivity piezoresistive cantilevers under 1000 angstrom thick

Ultrathin, high-sensitivity piezoresistive cantilevers were constructed usi ng vapor-phase epitaxy to grow the conducting layer. A fourfold reduction i n thickness was achieved over the thinnest implanted piezoresistive cantile vers, allowing improved force or displacement sensitivity and increased ban dwidth. In cantilevers 890 Angstrom thick, the dopant is well confined to t he surface, and the sensitivity is 70% of the theoretical maximum. A cantil ever fabricated for high force resolution has a minimum detectable force of 8.6 fN/root Hz in air. Additionally, the 1/f noise is shown to follow the relation proposed by Hooge [Phys. Lett A 29, 139 (1969)], increasing in inv erse proportion to the number of carriers. (C) 1999 American Institute of P hysics. [S0003-6951(99)01728-3].