  A simple scalable scheme is reported for fabricating suspended carbon
nanotube field effect transistors (CNT-FETs) without exposing pristine as-grown
carbon nanotubes to subsequent chemical processing. Versatility and ease of the
technique is demonstrated by controlling the density of suspended nanotubes and
reproducing devices multiple times on the same electrode set. Suspending the
carbon nanotubes results in ambipolar transport behavior with negligible
hysteresis. The Hooges constant of the suspended CNT-FETs (2.6 x 10-3) is about
20 times lower than for control CNT-FETs on SiO2 (5.6 x 10-2).
