A method is provided for forming a vertical transistor memory cell structure with back-to-back FET cells which are formed in a planar semiconductor substrate with a plurality of deep trenches having vertical FET devices and a plurality of capacitors each located in a separate trench that is formed in the semiconductor substrate. Bilateral outdiffusion strap regions are formed extending into a doped semiconductor well region in the substrate. There are confronting pairs of outdiffusion strap regions extending from adjacent deep benches into the doped well region. An isolation diffusion region is formed in the doped well separating the confronting isolation diffusion regions by extending therebetween.