Effect of Step Gate Work Function on InGaAs p-TFET for Low Power Switching Applications

Area of Science:

• Semiconductor device physics
• Materials science

Background:

• Advanced field-effect transistors (FETs) are crucial for low-power electronics.
• Dual Material Gate (DMG) technology offers a method to modulate device characteristics.
• Understanding work function effects is key to optimizing transistor performance.

Purpose of the Study:

• To theoretically investigate the impact of step gate work function on InGaAs p-type FET (p-TFET) performance.
• To analyze device parameters for both low-power digital and analog applications.
• To determine the optimal gate work function difference for specific applications.

Main Methods:

• Theoretical investigation of InGaAs p-TFET devices with DMG structure.
• Analysis of device performance based on gate work function difference (Δϕ_S-D).
• Variation of drain-side gate electrode work function while keeping the source-side fixed (Pt, ϕ_S = 5.65 eV).

Main Results:

• Device performance is sensitive to the gate work function difference due to altered electric field and carrier distributions.
• A high gate work function difference (Δϕ_S-D = 1.02 eV) yielded a low subthreshold slope (30.89 mV/dec) and off-state current (0.39 pA/µm), indicating suitability for low-power digital applications.
• A low gate work function difference (Δϕ_S-D = 0.61 eV) resulted in high transconductance (g_m) and cut-off frequency (f_T), making the device suitable for low-power analog applications.

Conclusions:

• The InGaAs p-TFET with DMG structure demonstrates tunable performance based on step gate work function.
• The device is a promising candidate for future low-power digital applications with optimized high work function difference.
• The device is also viable for future low-power analog applications with optimized low work function difference.