Determining the Electronic Performance Limitations in Top-Down-Fabricated Si Nanowires with Mean Widths Down to 4 nm

Abstract

Silicon nanowires have been patterned with mean widths down to 4 nm using top-down lithography and dry etching. Performance-limiting scattering processes have been measured directly which provide new insight into the electronic conduction mechanisms within the nanowires. Results demonstrate a transition from 3-dimensional (3D) to 2D and then 1D as the nanowire mean widths are reduced from 12 to 4 nm. The importance of high quality surface passivation is demonstrated by a lack of significant donor deactivation, resulting in neutral impurity scattering ultimately limiting the electronic performance. The results indicate the important parameters requiring optimization when fabricating nanowires with atomic dimensions.

Analysis of Ge micro-cavities with in-plane tensile strains above 2 %

“…The structures were subsequently dry etched in a mixed SF 6 and C 4 F 8 recipe through to the Si layer, with an etch recipe which has previously demonstrated low electrical [18,19] and optical damage [4] to devices. A wet etch in tetramethylammonium hydroxide (TMAH) and isopropyl alcohol (IPA) was used to selectively etch the Si thereby undercutting the structures.…”

Experimental and simulation study of a high current 1D silicon nanowire transistor using heavily doped channels

“…Currently work is being undertaken toward calibrating the DG correction to the 2D Schrödinger -3D Poisson solver, used for accurate simulation of quantum confinement effects. Also the fabrication techniques and electronic properties of similar ungated and larger nanowires have been published elsewhere [7,8]. The drain current as a function of gate voltage, measured for nanowires with three different diameters, is presented in Fig.…”

(Invited) The Use of Silicon-Germanium Superlattices in Thermoelectric Devices and Microfabricated Generators

“…Figure 6 presents cartoons of the two devices microfabricated to allow the extraction of the a and k values. Photolithography was used before a mesa pattern was etched using SF 6 and C 4 F 8 mixed etch process (18) which has demonstrated very low levels of damage (19). Metal contacts were patterned using Ag (1% Sb) annealed at 400 ˚C at the top and bottom of the mesa to provide electrical Ohmic contacts (20).…”