Use of NH3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices
| Autor: | S.O. Park, Ki-Hyun Hwang, Dong-ho Ahn, J.H. Park, D.-H. Ko, Zhenhua Wu, Jung-Sung Kim |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Void (astronomy) Materials science business.industry Annealing (metallurgy) Metals and Alloys 02 engineering and technology Surfaces and Interfaces GeSbTe 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Cell size Phase-change memory chemistry.chemical_compound chemistry Transmission electron microscopy 0103 physical sciences Vaporization Materials Chemistry Optoelectronics Dry etching 0210 nano-technology business |
| Zdroj: | Thin Solid Films. 616:502-506 |
| ISSN: | 0040-6090 |
| DOI: | 10.1016/j.tsf.2016.08.065 |
| Popis: | As the cell size of phase change memory devices decreases to less than 100 nm, the dry etch used for cell patterning becomes extremely critical because of its impact on the properties of memory cells. HBr gas has been known as the etchant that can minimize surface etching damage to GeSbTe-based phase change materials. However, the findings reported herein show that the HBr etch of CGeSbTe (CGST) films causes voids after annealing at temperatures below 400 °C due to the vaporization of volatile bromides (GeBr4, SbBr2, and TeBr2) that form when bromine diffuses during the etch. In this investigation, we report on the use of NH3 etchants to suppress the formation of volatile compounds and thereby eliminate void formation in CGST materials. The properties of NH3 etchants were compared to those of HBr etchants as a function of both etch rate and profiles. The effects of void suppression as observed in transmission electron microscopy images of as-etched CGST film after annealing indicate that phase change memory devices etched using an NH3 exhibited enhanced set cycles that were over 108 superior to results of HBr etchants by 2 orders of magnitude. |
| Databáze: | OpenAIRE |
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