Semiconductor memory device and method of fabricating the same

A semiconductor memory device, comprising:

• a device isolation pattern disposed in a substrate to define a plurality of active regions;
• a recess region defined in the device isolation pattern and the substrate and having a first inner side surface and a second inner side surface opposite to each other;
• a first impurity region and a second impurity region disposed in a first active region of the plurality of active regions and a second active region of the plurality of active regions, respectively, the first impurity region being provided in the substrate exposed through a bottom surface of the recess region;
• a bit-line contact, which directly contacts the first impurity region and is disposed in the recess region;
• a first protection spacer covering a lower portion of the first inner side surface of the recess region;
• and
• a second protection spacer covering a lower portion of the second inner side surface of the recess region,
• wherein the first protection spacer and the second protection spacer comprise the same material and have different shapes from each other.

A semiconductor memory device, comprising:

• a device isolation pattern disposed in a substrate to define a plurality of active regions;
• a recess region defined in the device isolation pattern and the substrate and having a first inner side surface and a second inner side surface opposite to each other;
• a first impurity region and a second impurity region disposed in a first active region of the plurality of active regions and a second active region of the plurality of active regions, respectively, the first impurity region being provided in the substrate exposed through a bottom of the recess region;
• a bit-line contact, which directly contacts the first impurity region and is disposed in the recess region;
• a first protection spacer covering the first inner side surface of the recess region;
• and
• a second protection spacer covering the second inner side surface of the recess region,
• wherein the first protection spacer directly contacts the substrate, and
• wherein the second protection spacer is spaced apart from the substrate.