The 3D double layer Ω-type FETs with ferroelectric HfZrO2 gate served for one-transistor (1T) architecture is demonstrated and studied for memory reliability. The high endurance is presented more than 106 cycles P/E with 4V. Multi-domain model integrated with TCAD is proposed by adding a coupling coefficient for the polarization gradient term of the free energy, and calculating for nanosheet GAA-FETs. The polarization orientation is assigned randomly by Gaussian distribution into individual domain for multi-dimensional 3D device simulation. The data retention is degraded due to depolarization field occurrence at the corner by modeling results. The feasible structure paves the candidate for emerging memory applications.