Fast crystallization temperature of phase change materials in nano-second range and its application of multi-levels recording

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360003
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Gunma University
• Principal Investigator: HOSAKA Sumio 群馬大学, 大学院理工学府, 教授 (10334129)
• Co-Investigator(Kenkyū-buntansha): KUWABARA Masashi 国立研究開発法人産業技術総合研究所, 電子光技術研究部門・メゾ構造制御グループ, 研究員 (60356954)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 相変化メモリ / 結晶化 / 結晶化温度 / 階段パルス / 結晶化温度時間特性 / 電流加熱シミュレーション / 多値記録

Outline of Final Research Achievements

Nano-second dynamic crystallization temperature of phase change material, Ge2Sb2Te5 and GeTe were investigated using experiments with step-wise pulse and FEM simulations. After melting, crystallization of the materials were measured with resistance to obtain the crystallization yields from the change. The crystallization temperatures were estimated by associating these data. While the pulse width of 300ns was required for complete crystallization of Ge2Sb2Te5, 40 ns was for the complete crystallization of GeTe. Furthermore, while the crystallization temperature of Ge2Sb2Te5 of about 320 C was estimated at 100ns-pulse width, the temperature of GeTe of about 180 C was estimated at 40 ns. The temperatures increased as the pulse widths were short. It is clear that GeTe has fast mobile atoms from amorphous to crystal state compared with Ge2Sb2Te5 We can estimate crystallization temperature in a range of nano second using this method.

Free Research Field

ナノテクノロジ