InAs FinFETs Performance Enhancement by Superacid Surface Treatment

In this paper, a post superacid (SA) treatment was proposed to enhance the performance of InAs FinFETs on SiO
₂
/Si substrates. Typically, the subthreshold swing (SS) has reduced from 217 to 170 mV/decade and the transconductance (
${g}_{m}$
) has increased from 6.44 to 26.5
$\mu \text{S}/\mu \text{m}$
after SA treatment. It was found that the interfacial In
₂
O
₃
at the InAs/ZrO
₂
interface was effectively reduced after SA treatment due to the strong protonating nature of the SA solution. As a result, the interface trap density was reduced leading to a pronounced reduction of sheet resistance after SA treatment. The modeling of transfer characteristics indicates that the carrier mobility is enhanced by 5.8~7.1 folds after SA treatment due to interfacial traps reduction. The results suggest that SA treatment can be potentially extended to other III–V MOSFETs to enhance the device performances.