Application of forksheet transistor in operational transconductance amplifier

This work presents, for the first time, experimental data on forksheet transistor used in the design of operational transconductance amplifiers (OTA), highlighting their potential for application in analog circuits. The OTA was designed for three different transistor efficiencies: gm/I_D of 5, 8 and 11 V⁻¹. The experimental n-type forksheet used in this work presents a sheet thickness of H_FS = 7 nm, sheet width of W_FS = 23 nm and a transistor channel length of L_G = 70 nm. When the gm/I_D increases from 5 to 11 V⁻¹, the drain current and the transconductance decrease, which improves the OTA voltage gain (Av ∝ gm/I_D) from 49 dB to 63 dB, the total power dissipation (Power ∝ I_D) also improves (decreases) from 528 μW to 129 μW, while degrades the Gain-Bandwidth Product (GBW) from 343 MHz to 196 MHz (GBW ∝ gm). Depending on the application, the OTA bias conditions must be set appropriately due to the trade-off between Av and GBW. The obtained results show that the forksheet can be used for analog circuits such as OTA, for application in mixed-signal integrated circuits using this technology.