An integrated circuit includes an SOI substrate with a unitary N+ layer below the BOX, a P region in the N+ layer, an eDRAM with an N+ plate, and logic/SRAM devices above the P region. The P region functions as a back gate of the logic/SRAM devices. An optional intrinsic (undoped) layer can be formed between the P back gate layer and the N+ layer to reduce the junction field and lower the junction leakage between the P back gate and the N+ layer. In another embodiment an N or N+ back gate can be formed in the P region. The N+ back gate functions as a second back gate of the logic/SRAM devices. The N+ plate of the SOI eDRAM, the P back gate, and the N+ back gate can be electrically biased at the same or different voltage potentials. Methods to fabricate the integrated circuits are also disclosed.