The semiconductor memory device includes: a first substrate including a peripheral circuit, first conductive contact patterns connected to the peripheral circuit, and a first upper insulating layer having grooves exposing the first conductive contact patterns; a second substrate including a memory cell array, a second upper insulating layer disposed on the memory cell array, the second upper insulating layer formed between the memory cell array and the first upper insulating layer, second conductive contact patterns protruding through the second upper insulating layer into an opening of the grooves; and conductive adhesive patterns filling the grooves to connect the second conductive contact patterns to the first conductive contact patterns.

There are provided a semiconductor memory device and a method for manufacturing the same. The semiconductor memory device includes: a first substrate including a peripheral circuit, first conductive contact patterns connected to the peripheral circuit, and a first upper insulating layer having grooves exposing the first conductive contact patterns; a second substrate including a memory cell array, a second upper insulating layer disposed on the memory cell array, the second upper insulating layer formed between the memory cell array and the first upper insulating layer, a second conductive contact patterns protruding through the second upper insulating layer into an opening of the grooves; and conductive adhesive patterns filling the grooves to connect the second conductive contact patterns to the first conductive contact patterns.

A lead-free solder alloy composition includes a lead-free solder alloy; and a flower-shaped metal nano-particle including a metal core and protrusion portions extending from a surface of the metal core, wherein the metal core and the protrusion portions of the metal nano-particle include only one metal element.