X-ray photoelectron spectroscopic study of Ge2Sb2Te5 etched by fluorocarbon inductively coupled plasmas

Kang, S.‐K.; Oh, Jong Sik; Park, B. J.; Kim, S. W.; Lim, Janis; Yeom, Geun‐Young; Kang, Chang Jin; Min, Gu

doi:10.1063/1.2967468

Cited by 16 publications

(11 citation statements)

References 8 publications

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“…What's more, two smaller additional peaks are presented in both Sb 3d and Te 3d spectra, which can be attributed to Sb-F x (the peaks at 530.67 eV and 540.0 eV in Sb 3d spectra) and Te-F x (the peaks at 576.57 eV and 587.04 eV in Te 3d spectra), respectively. 22 With the increasing time of Ar ion sputtering, the two small peaks in both Sb 3d and Te 3d spectra are gradually undetected, while the Sb 3d and Te 3d peaks slowly appear. From Fig.…”

Section: Resultsmentioning

confidence: 95%

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Wang

Liu

Jin

et al. 2016

ECS J. Solid State Sci. Technol.

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The investigation of reactive-ion-etching (RIE) characteristics and mechanisms for Ti-Sb-Te (TST) new phase change material in CHF3/O2/Ar plasmas was carried out in this paper. The effects of three experimental parameters, gas ratio, gas pressure and input radio frequency (RF) power on variations of etch rate, surface root-mean-square (RMS) roughness and profile were investigated. Within the range of our experimental conditions, the maximum etch rate with ∼83 nm/min, a smooth surface with RMS less than 1 nm and a highly anisotropic profile are obtained using the optimized process conditions (8% oxygen content, input power of 300 W, gas pressure of 30 mTorr). The surface roughness is strongly reduced with the addition of oxygen, but sharply increased at higher gas pressure. Surface analysis using X-ray photoelectron spectroscopy (XPS) reveal that surface of etched TST film is mainly fluorinated by forming TiFx, SbFx, and TeFx. According to spectra of Sb 3d and Te 3d, a slight shift of peaks to a higher energies (∼0.6 eV) on the etched surface can be seen, indicting the surface degradation after etching process.

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Section: Resultsmentioning

confidence: 95%

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Wang

Liu

Jin

et al. 2016

ECS J. Solid State Sci. Technol.

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“…5) We demonstrated that less damaged etching can be performed with a lower F/C ratio fluorocarbon gas owing to the thicker C-F polymer formed on the GST surface and sidewalls during the etching, which protects against the diffusion of fluorine radicals to the GST film. In this article, the etching of GST with three types of halogen gas is described and the extent of the surface damage of GST during the etching by different halogen-gas-based inductively coupled plasmas (ICPs) such as CF 4 , Cl 2 , and HBr is investigated.…”

Section: Introductionmentioning

confidence: 90%

“…The 100-nm-thick GST samples were prepared on SiO 2 /Si substrates by rf magnetron co-sputtering from GeTe and Sb 2 Te 3 targets and some of the samples were patterned with an SiO 2 hard mask after depositing a Ti (as an adhesion layer of 5 nm)/ TiN layer on the GST films similarly to those described in our previous article. 5) The composition of the sputterdeposited GST was known to be Ge : Sb : Te ¼ 22 : 22 : 56 (XPS analysis showed that the actual composition was Ge : Sb : Te ¼ 26 : 26 : 48). The etch depth was measured using a surface profilometer (Tencor Alpha-step 500).…”

Section: Experimental Methodsmentioning

confidence: 99%

Etch Damage of Ge₂Sb₂Te₅for Different Halogen Gases

Kang

Jeon

Park

et al. 2011

Jpn. J. Appl. Phys.

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Etch damage of Ge 2 Sb 2 Te 5 (GST) has been investigated after etching in halogen inductively coupled plasmas (ICPs) such as CF 4 , Cl 2 , and HBr. X-ray photoelectron spectra of Ge, Sb, and Te on the etched surfaces showed different depths of etch damage depending on the halogen-based plasmas. The blank GST etched by CF 4 showed a lower total-halogen-percentage remaining on the etched surface than that etched by Cl 2 even though the depth of halogenations was the deepest for the GST etched by CF 4 owing to the highest reactivity. However, when a GST feature masked by SiO 2 /Ti/TiN was etched, owing to the reaction of O from the SiO 2 mask and C from CF 4 , a thinner/or no C-F polymer appeared to be formed on the etched sidewall; therefore, the highest halogenation was observed on the GST etched by CF 4 . Among the halogen-gases investigated, HBr showed the lowest damage due to the lowest reactivity. #

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“…18 Many studies on the etching of GST materials and their damage characteristics can be found in previous studies. [19][20][21][22][23][24] However, the etch characteristics OTS materials including the damages by the etching using halogen gas-based plasmas have not been reported yet, and it is very important to understand the effect of the halogen etch gases for low-damage OTS etching.…”

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confidence: 99%

Etch Damages of Ovonic Threshold Switch (OTS) Material by Halogen Gas Based-Inductively Coupled Plasmas

Park

Kim

Lee

et al. 2019

ECS J. Solid State Sci. Technol.

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The ovonic threshold switch (OTS) selector device is suitable for a phase-change random access memory (PRAM) requiring instantaneous high-output power due to the high-current density and high-speed operation. An amorphous chalcogenide-based compound composed of As-Te-Ge is a candidate for OTS materials and has excellent selector performances such as low leakage current, fast switching speed, scalability, and thermal stability. However, this material is known to suffer damage due to easy halogenation when exposed to halogen gas-based plasmas. In this study, the etch damages of OTS surface during the halogen gas based-inductively coupled plasma (ICP)-reactive ion etching (RIE) using CF4 and Cl2 were investigated. The OTS etched with Cl2 showed a higher etch rate compared to that with CF4. However, the surface roughness was lower for the OST etched with Cl2 than that etched with CF4. Also, the thickness of halogenated layer during the etching was also thinner for Cl2-etched OST than CF4-etched OST. Therefore, compared to CF4-etched OST, Cl2-etched OST was less damaged by the etching. In addition, it is found that, among the OST components of As, Te, and Ge, Ge was mostly halogenated while As and Te are not significantly halogenated during the etching.

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X-ray photoelectron spectroscopic study of Ge2Sb2Te5 etched by fluorocarbon inductively coupled plasmas

Cited by 16 publications

References 8 publications

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Etch Damage of Ge₂Sb₂Te₅for Different Halogen Gases

Etch Damages of Ovonic Threshold Switch (OTS) Material by Halogen Gas Based-Inductively Coupled Plasmas

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X-ray photoelectron spectroscopic study of Ge2Sb2Te5 etched by fluorocarbon inductively coupled plasmas

Cited by 16 publications

References 8 publications

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF3/O2/Ar Plasma for Nano-Devices

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF3/O2/Ar Plasma for Nano-Devices

Etch Damage of Ge2Sb2Te5for Different Halogen Gases

Etch Damages of Ovonic Threshold Switch (OTS) Material by Halogen Gas Based-Inductively Coupled Plasmas

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Product

Resources

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Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Etching Characteristics and Mechanisms of Ti-Sb-Te Phase Change Material in CHF₃/O₂/Ar Plasma for Nano-Devices

Etch Damage of Ge₂Sb₂Te₅for Different Halogen Gases