First Demonstration of a-IGZO GAA Nanosheet FETs Featuring Achievable SS=61mV/dec,Ioff<-7μA/μm, DIBL =44mV/V, Positive VT, and Process Temp. of 300 °C
Journal
Digest of Technical Papers - Symposium on VLSI Technology
Journal Volume
2023-June
ISBN
9784863488069
Date Issued
2023-01-01
Author(s)
Abstract
The first amorphous InGaZnO (a-IGZO) gate-all-around (GAA) nanosheet FET is demonstrated. All of the process temperatures are below 300°C, showing great back-end-of-line (BEOL) compatibility. The channel release is achieved by sophisticated reactive-ion etch (RIE) with extremely high etching selectivity of the SiN sacrificial layer over the a-IGZO channel. A novel composite field oxide (FOX) is exploited to form an etching stop layer and avoid gate leakage. The device with gate length (L) of 52nm shows Ioff < 10-7 μA/mum (detection limit), high Ion/Ioff > 1.3 × 108, the enhancement mode with the positive threshold voltage (VT) of 3.5V, and the clear saturation region in the output characteristic. Moreover, the smallest SS of 61mV/dec among all oxide semiconductor nanowire /nanosheet devices is achieved with the gate length of 150nm.
Type
conference paper