Yoo Changhyeon, Shin Han-Kyun, Han Sang Sub, Lee Seohui, Lee Chung Won, Song Yu-Jin, Bae Tae-Sung, Yoo Seung Jo, Cao Justin, Kim Jung Han, Lee Hyo-Jong, Chung Hee-Suk, Jung Yeonwoong
NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States.
Department of Materials Science and Engineering, Dong-A University, Busan 49315, Republic of Korea.
Nano Lett. 2024 Oct 2. doi: 10.1021/acs.nanolett.4c03127.
Monocrystalline chalcogenide thin films in freestanding forms are very much needed in advanced electronics such as flexible phase change memories (PCMs). However, they are difficult to manufacture in a scalable manner due to their growth and delamination challenges. Herein, we report a viable strategy for a wafer-scale epitaxial growth of monocrystalline germanium telluride (GeTe) membranes and their deterministic integrations onto flexible substrates. GeTe films are epitaxially grown on Ge wafers via a tellurization reaction accompanying a formation of confined dislocations along GeTe/Ge interfaces. The as-grown films are subsequently delaminated off the wafers, preserving their wafer-scale structural integrity, enabled by a strain-engineered spalling method that leverages the stress-concentrated dislocations. The versatility of this wafer epitaxy and delamination approach is further expanded to manufacture other chalcogenide membranes, such as germanium selenide (GeSe). These materials exhibit phase change-driven electrical switching characteristics even in freestanding forms, opening up unprecedented opportunities for flexible PCM technologies.
在先进电子设备（如柔性相变存储器（PCM））中，非常需要独立形式的单晶硫族化物薄膜。然而，由于其生长和分层挑战，难以以可扩展的方式制造。在此，我们报告了一种可行的策略，用于在晶圆规模上外延生长单晶碲化锗（GeTe）膜，并将其确定性集成到柔性基板上。通过碲化反应，伴随沿GeTe/Ge界面形成受限位错，在Ge晶圆上外延生长GeTe膜。随后，通过利用应力集中位错的应变工程剥落方法，将生长的薄膜从晶圆上分层剥离，保持其晶圆规模的结构完整性。这种晶圆外延和分层方法的通用性进一步扩展到制造其他硫族化物膜，如硒化锗（GeSe）。这些材料即使以独立形式也表现出相变驱动的电开关特性，为柔性PCM技术开辟了前所未有的机会。
