Comparative Study of the Low-Frequency-Noise Behaviors in a-IGZO Thin-Film Transistors With <tex> $\hbox{Al}_{2}\hbox{O}_{3}$</tex> and <tex> $\hbox{Al}_{2}\hbox{O}_{3}/\hbox{SiN}_{x}$</tex> Gate Dielectrics

다국어 초록 (Multilingual Abstract)

<P>A comparative study is made of the low-frequency noise (LFN) in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with Al<SUB>2</SUB>O<SUB>3</SUB> and Al<SUB>2</SUB>O<SUB>3</SUB>/SiN<SUB>x</SUB> gate dielectrics. The LFN is proportional to 1/f<SUP>gamma</SUP>, with gamma ~ 1 for both devices, but the normalized noise for the Al<SUB>2</SUB>O<SUB>3</SUB>/SiN<SUB>x</SUB> device is two to three orders of magnitude lower than that for the Al<SUB>2</SUB>O<SUB>3</SUB> device. The mobility fluctuation is the dominant LFN mechanism in both devices, but the noise from the source/drain contacts becomes comparable to the intrinsic channel noise as the gate overdrive voltage increases in Al<SUB>2</SUB>O<SUB>3</SUB>/SiN<SUB>x</SUB> devices. The SiN<SUB>x</SUB> interfacial layer is considered to be very effective in reducing LFN by suppressing the remote phonon scattering from the Al<SUB>2</SUB>O<SUB>3</SUB> dielectric. Hooge's parameter is extracted to ~6.0 times 10<SUP>-3</SUP> in Al<SUB>2</SUB>O<SUB>3</SUB>/SiN<SUB>x</SUB> devices.</P>