US Patent 11856782 Three-dimensional memory device and method

3D memory array devices and methods of manufacturing are described herein. A method includes etching a first trench and a second trench in a multilayer stack, the multilayer stack including alternating dielectric layers and sacrificial layers. The method further includes forming a word line by replacing a sacrificial layer with a conductive material. Once the word line has been formed, a first transistor is formed in the first trench, the first transistor including a first channel isolation structure. A cut channel plug is formed in the second trench, a centerline of the cut channel plug being aligned with a centerline of the channel isolation structure. The method further includes forming a second transistor in the second trench adjacent the cut channel plug, the word line being electrically coupled to the first transistor and the second transistor.