Polarity-controllable MoS₂ transistor for adjustable complementary metal-oxide-semiconductor inverter applications

Che-Yu Lin^1,5*, Kristan Bryan Simbulan², Chuan-Jie Hong³, Kai-Shin Li⁴, Yuan-Liang Zhong³, Yan-Kuin Su^1,5, Chih-Chiang Yang^1,5, Yann-Wen Lan²

¹1Institute of Microelectronics, National Cheng Kung University, Tainan, Taiwan
²Department of Physics, National Taiwan Normal University, Taipei, Taiwan
³Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chungli, Taiwan
⁴National Nano Device Laboratories, National Applied Research Laboratories, Hsinchu, Taiwan
⁵Green Energy Technology Research Center, Department of Electrical Engineering, Kun Shan University, Tainan, Taiwan

* Presenter:Che-Yu Lin, email:jylin1220@gmail.com

In this work, we introduce a MoS₂ -based field effect transistor that can alternately operate either as a p-type or an n-type semiconductor in the identical device. The proposed device is built with an adjustable threshold voltage (V_th), which can be varied by adding a layer of plasma-oxidized dielectric at the top gate structure. This facilitates a surplus of oxygen due to the relatively thin grown dielectric layer and creation of negative charges in that layer instead of the usual ones of positive polarization in the bottom dielectric layer. Consequently, the V_th shifts and the top gate structure switch from the typical n-type to p-type while n-type behaviour remains in the application of bottom-gate voltages. The V_th can be tuned further by applying a gate pulse input at the top gate. Accordingly, we have demonstrated the complementary logic inverters with the adjustable device characteristic that is controllable by the polarity of charges induced in the device’s oxide layer. This is a big step towards the concurrent implementation of both n-type and p-type characteristics in a single device.

Keywords: Polarity-controllable, adjustable, MoS₂, CMOS inverter, transistor