Method for forming memory array including strings of memory cells

A method for forming a memory array including strings of memory cells includes forming a lower portion of a stack on a substrate that will include vertically alternating first and second layers. The stack includes regions of memory blocks that are laterally spaced apart. The material of the first layer has a different composition than the material of the second layer. Horizontal elongated lines are formed in the lower portion, the lines being individually between laterally immediately adjacent memory block regions. The lines include a sacrificial material. The lines individually include laterally opposing protrusions longitudinally along them in a lowermost one of the first layers. The vertically alternating first and second layers of an upper portion of the stack are formed over the lower portion and the line, and a string of channel material is formed that extends through the first and second layers in the upper portion to the lower portion. 一种用于形成包括存储器单元串的存储器阵列的方法包括：在衬底上形成将包括竖直交替的第一层和第二层的堆叠的下部部分。所述堆叠包括横向间隔