Three-dimensional NAND memory device and manufacturing method

A method of forming a three-dimensional (3D) NAND memory device includes forming a gate line slot through alternating layers of oxide layers and conductive material layers, where the conductive material layers are also formed on sidewalls and a bottom of the gate line slot; performing a first etching process to remove portions of the conductive material layer from sidewalls and bottoms of the gate line slots and from between adjacent oxide layers, thereby exposing portions of the oxide layers in the gate line slots; removing an exposed part of the oxide layer on the side wall of the gate line gap; and executing a second etching process to remove residues of the conductive material layer in the gate line gap. 一种形成三维(3D)NAND存储器器件的方法，包括：形成穿过氧化物层和导电材料层的交替层的栅极线缝隙，其中，导电材料层还形成在栅极线缝隙的侧壁和底部上；执行第一蚀刻工艺，以从栅极线缝隙的侧壁和底部并且从相邻氧化物层之间去除导电材料层的部分，由此暴露氧化物层的在栅极线缝隙中的部分；去除氧化物层的在栅极线缝隙的侧壁上的暴露部分；以及执行第二蚀刻工艺，以去除栅极线缝隙中的导电材料层的残留物。