Soret-Effect Induced Phase-Change in a Chromium Nitride Semiconductor Film
Yi Shuang, Shunsuke Mori, Takuya Yamamoto, Shogo Hatayama, Yuta Saito, Paul Fons, Yun‐Heub Song, Jin Pyo Hong, Daisuke Ando, Yuji Sutou
Abstract
High Resolution Image Download MS PowerPoint Slide Phase-change materials such as Ge–Sb–Te (GST) exhibiting amorphous and crystalline phases can be used for phase-change random-access memory (PCRAM). GST-based PCRAM has been applied as a storage-class memory; however, its relatively low ON/OFF ratio and the large Joule heating energy required for the RESET process (amorphization) significantly limit the storage density. This study proposes a phase-change nitride, CrN, with a much wider programming window (ON/OFF ratio more than 10 5 ) and lower RESET energy (one order of magnitude reduction from GST). High-resolution transmission electron microscopy revealed a phase-change from the low-resistance cubic CrN phase into the highly resistive hexagonal CrN 2 phase induced by the Soret-effect. The proposed phase-change nitride could greatly expand the scope of conventional phase-change chalcogenides and offer a strategy for the next-generation of PCRAM, enabling a large ON/OFF ratio (∼10 5 ), low switching energy (∼100 pJ), and fast operation (∼30 ns).