Sunday, January 22, 2012

US Patent 8097922 - Nanoscale transistor with enhanced carrier mobility

Strain engineering is a technique used in transistor manufacture to increase the carrier mobility and transistor switching speed but can also result in a reduction in thermal conductivity leading to overheating. This patent from the Regents of the University of California teaches an alternative way to increase transistor speed using a high thermal conductivity nanoscale barrier shell. Claim 1 reads:

1. A transistor having high carrier mobility comprising:

a drain structure;

a source structure;

a channel formed of a channel material and extending between the drain structure and the source structure, wherein at least one of a thickness and a diameter of the channel is in an order of a thermal phonon wavelength of the channel material;

a barrier shell formed of a barrier shell material having an acoustic impedance of at least 2 times an acoustic impedance of the channel material that at least substantially surrounds a portion of the channel such that the barrier shell confines acoustic phonons in the channel material of the channel;

a gate structure; and

a gate insulator between a portion of the gate structure and the barrier shell.