Abstract: A semiconductor phase-change memory device comprises a data line disposed on a semiconductor substrate and a data storage structure disposed under the data line and having a concave portion extending in a direction along the data line. A data contact structure is configured to contact the data storage structure, and having a lower portion filling the concave portion of the data storage structure and an upper portion surrounding at least a lower portion of the data line. Each of sidewalls of the data storage structure is disposed at substantially the same plane as a corresponding one of sidewalls of the upper portion of the data contact structure.