Semiconductor device and method of fabricating the same
A semiconductor device includes a device isolation pattern on a substrate to define active patterns, a gate electrode crossing the active patterns, first and second impurity regions in each of the active patterns and on both sides of the gate electrode, a bit line crossing the gate electrode, a first contact electrically connecting the first impurity region to the bit line, and a second contact electrically connected to the second impurity region. The second contact includes a vertically-extended portion covering an upper side surface of the second impurity region.
1. A method of fabricating a semiconductor device, comprising:
forming a gate electrode in a substrate with active patterns, the active patterns defined by a device isolation pattern;
forming first and second impurity regions in each of the active patterns and on both sides of the gate electrode;
forming an interlayered insulating pattern on the substrate with the first and second impurity regions;
forming a preliminary contact to penetrate the interlayered insulating pattern and be electrically connected to the first impurity region;
forming a conductive layer on the preliminary contact;
etching the conductive layer and the preliminary contact to form a bit line crossing the gate electrode and a contact, respectively;
forming a first contact hole to expose top surfaces of the second impurity region and the device isolation pattern adjacent to the second impurity region; and
etching the top surface of the device isolation pattern exposed by the first contact hole,
wherein the forming an interlayered insulating pattern includes,
forming an interlayered insulating layer on the substrate with the first and second impurity regions, and
etching the interlayered insulating layer to form a second contact hole exposing a portion of the first impurity region and a portion of the device isolation pattern adjacent to the first impurity region,
wherein the forming a preliminary contact includes,
etching the exposed portions of the first impurity region and the device isolation pattern to form a recess region connected to the second contact hole, and
filling the second contact hole and the recess region with a conductive material, and
wherein the etching the conductive layer and the preliminary contact includes,
forming a first mask pattern on the conductive layer, the first mask pattern extending parallel to the bit line,
etching the conductive layer using the first mask pattern as an etch mask to form the bit line, and
etching the preliminary contact using the first mask pattern and the bit line as an etch mask to form the contact.
2. The method of claim 1 , wherein the forming a first contact hole comprises:
forming a first spacer to cover a side surface of the bit line;
forming an etch-stop layer on the substrate to cover the first spacer;
forming a second mask pattern on the first mask pattern, the second mask pattern extending parallel to the bit line; and
etching the etch-stop layer and the interlayered insulating pattern using the first and second mask patterns as an etch mask to form the first contact hole.
3. The method of claim 2 , further comprising:
etching a side surface of the interlayered insulating pattern exposed by the first contact hole,
wherein the etching etches the top surface of the device isolation pattern.
4. The method of claim 1 , wherein the etching the top surface of the device isolation pattern selectively etches an oxide layer of the device isolation pattern using a dry etching process.
5. The method of claim 1 , further comprising:
forming a nitride layer on the substrate to fill the recess region and cover side surfaces of the contact and the bit line; and
performing a wet etching process on the nitride layer to form a nitride pattern in the recess region after the etching the conductive layer and the preliminary contact.