Low temperature processed complementary metal oxide semiconductor (CMOS) device by oxidation effect from capping layer.

Zhenwei Wang,Nini Wei,J. A. Caraveo-Frescas,H. N. Alshareef,M. N. Hedhili,Hala A. Al-Jawhari,Pradipta K. Nayak

doi:10.1038/srep09617

Abstract

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

Highlights

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer
The capacitance and current-voltage curve for the ATO dielectric is presented in Figure S2, the average capacitance is found about 55 nFcm[22]
For the p-type TFT, single SnO layer was used as active layer, while Cu2O/SnO bilayer was used for the n-type TFT, as depicted in Figure 1(d) and (e)

Summary

Introduction

Both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The oxidation process can be realized by annealing at temperature as low as 1906C in air, which is significantly lower than the temperature generally required to form tin dioxide Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. We report a novel approach of transforming SnO to SnO2 phase at PDA temperature as low as 190uC, www.nature.com/scientificreports which facilitates the fabrication of both p- and n-type TFTs on the same dielectric layer. Such low processing temperature was achieved by using a dual active layer structure (capping layer/SnO layer). Our method provides an alternative solution to lower the process temperature of high-temperature SnO2 phase, which can enlarge the selection range of TSOs applied on the temperature sensitive flexible substrates

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