High-Performance Automotive-Grade Phase-Change Memory Based on Single-Phase In ₃ Sb ₁ Te ₂

Phase-change memory (PCM) is a promising embedded nonvolatile memory technology. However, its reliable operation at elevated temperatures remains a critical materials challenge. In particular, the simultaneous realization of high-temperature data retention, wide resistivity contrast, and low resistance drift within a single PCM material system is limited by low crystallization temperature, phase instability, and elemental segregation during crystallization. In 3 Sb 1 Te 2 (IST) has been identified as a thermally stable PCM material, although its practical implementation is constrained by phase segregation occurring during crystallization, resulting in a narrowed usable memory window. Here, we demonstrate that these limitations can be overcome through stoichiometric control and single-phase thin-film deposition of IST. Structural and electrical characterization reveals suppressed phase instability and an enhanced resistivity contrast of approximately 5 orders of magnitude between amorphous and crystalline states at 155 °C. The amorphous phase remains thermally stable up to 267 °C, while both resistance states exhibit low drift coefficients over extended thermal stress. An activation energy of 3.72 eV enables a projected ten-year data retention at 150 °C. Device-level measurements further validate the material performance, showing stable threshold voltage characteristics, an ON/OFF ratio of ≈1.2 × 10 2, and a low SET state drift coefficient of 2.09 × 10 –4 at 155 °C. These results establish stoichiometric IST thin films as a robust electronic materials platform for thermally stable phase-change memory and high-temperature nonvolatile memory applications.