SEMICONDUCTOR MEMORY DEVICE AND PRODUCTION METHOD THEREOF

摘要

A semiconductor memory device according to an embodiment has a memory cell array including: a plurality of lower wirings extending in the first direction; a plurality of upper wirings extending in the second direction, the upper wirings placed above the plurality of lower wirings; a plurality of memory cells provided at respective crossings of the plurality of lower wirings and the plurality of upper wirings; and an interlayer insulating film provided between the plurality of memory cells adjacent in the second direction, and the device is characterized in that the upper wiring includes: an upper firing first section deposited on the memory cell; and an upper wiring second section deposited on the interlayer insulating film, the upper wiring second section larger in crystal grain size than the upper wiring first section, and an upper surface of the memory cell is lower than an upper surface of the interlayer insulating film.

主权项

1. A method for producing a semiconductor memory device, the method comprising:
when two directions crossing one another are referred to as a first direction and a second direction, whereas a direction crossing the first direction and the second direction is referred to as a vertical direction, forming a stacked body having a lower wiring layer formed on a semiconductor substrate, a memory cell layer formed on the lower wiring layer, and a plurality of interlayer insulating film dividing, in the first direction, the lower wiring layer and the memory cell layer into more than one section and extending in the second direction; removing an upper portion of the memory cell so that an upper surface of the memory cell layer is lower than an upper surface of the interlayer insulating film; and stacking an upper wiring layer on the memory cell layer and the interlayer insulating film.