ROBUST NUCLEATION LAYERS FOR ENHANCED FLUORINE PROTECTION AND STRESS REDUCTION IN 3D NAND WORD LINES

摘要

A silicon-containing nucleation layer can be employed to provide a self-aligned template for selective deposition of tungsten within backside recesses during formation of a three-dimensional memory device. The silicon-containing nucleation layer may remain as a silicon layer, converted into a tungsten silicide layer, or replaced with a tungsten nucleation layer. Tungsten deposition can proceed only on the surface of the silicon-containing nucleation layer or a layer derived therefrom in a subsequent tungsten deposition process.

主权项

1. A method of manufacturing a semiconductor device, comprising:
forming a stack of alternating layers comprising insulating layers and sacrificial material layers over a substrate; forming a plurality of memory openings through the stack; forming memory stack structures in the plurality of memory openings, each of the memory stack structures comprising, from outside to inside, a memory material layer, a tunneling dielectric layer, and a semiconductor channel; forming a backside via trench through the stack of alternating layers; forming backside recesses by removing the sacrificial material layers selective to the insulating layers employing an etchant introduced through the backside via trench; depositing a silicon-containing nucleation layer in the backside recesses; and forming at least one tungsten layer in the backside recesses after deposition of the silicon-containing nucleation layer; wherein control gate electrodes for the memory stack structures are formed at levels of the backside recesses; and wherein each of the control gate electrodes comprises a portion of the at least one tungsten layer.