Inversion-mode GaAs wave-shaped field-effect transistor on GaAs (100) substrate

Abstract

Inversion-mode GaAs wave-shaped metal-oxide-semiconductor field-effect transistors (WaveFETs) are demonstrated using atomic-layer epitaxy of La2O3 as gate dielectric on (111)A nano-facets formed on a GaAs (100) substrate. The wave-shaped nano-facets, which are desirable for the device on-state and off-state performance, are realized by lithographic patterning and anisotropic wet etching with optimized geometry. A well-behaved 1 μm gate length GaAs WaveFET shows a maximum drain current of 64 mA/mm, a subthreshold swing of 135 mV/dec, and an ION/IOFF ratio of greater than 107.

Sonication-Enhanced Alignment Relay Technique for the Orientation of Single-Walled Carbon Nanotubes

“…Field effect transistors (FETs) are popular in integrated circuits because they are low-power devices whose structure allows for n- and p-channels to be packed together onto a semiconducting surface. − The amount of transistors in processors doubles every few years; however, there is limit in the count of transistors that can fit in a space . This equates to a need of increasing processing speed and power, while approaching physical limitations. , There are many methods in development to either miniaturize or replace Si transistors, − but using single-walled carbon nanotubes (SWNTs) as the semiconducting connection between source and drain has shown great potential. , …”

“…In Figure 5a, the dropcast sample has prominent peaks for semiconducting tubes (15,8) and (17,4) and what could either be a (12,6) metallic or (12,5) semiconducting SWNTs at the 194 cm −1 position. 45 The smaller diameter SWNTs is removed when subjected to ART, so regardless if it was a sc-or m-SWNTs, it is selectively detached; therefore, there is no need to further investigate its true conductivity further.…”

“…Furthermore, in Figure 5b, the center peak of 1.46 nm diameter becomes more intense and represents the (17, 3) tube. The smaller tube possesses a 1.60 nm diameter and can possibly be determined to be the (17,6) SWNTs. Furthermore, the control at green laser frequency shows only two chiralities of tubes: (17, 3) and (17,6) to be present after ART.…”

“…The smaller tube possesses a 1.60 nm diameter and can possibly be determined to be the (17,6) SWNTs. Furthermore, the control at green laser frequency shows only two chiralities of tubes: (17, 3) and (17,6) to be present after ART. These are different from the (15,8) and (17,4) peaks that remain on the control red laser Raman in Figure 5a, and this observation is due to different SWNTs being more Raman active at different laser intensities.…”

“…These are different from the (15,8) and (17,4) peaks that remain on the control red laser Raman in Figure 5a, and this observation is due to different SWNTs being more Raman active at different laser intensities. 23,[39][40][41]43,46 With sonication, it is possible to differentiate that there is both 1.46 nm (17, 3) and 1.43 nm (13,8) tubes and that the larger diameter tube at 1.62 nm (17,6) remains and grows to be more intense. The peak of 1.43 nm was likely present throughout but could not be deconvoluted from being too broad of a peak and close to another signal of similar diameter (1.46 nm).…”