Fig. 1.
Etch rate of the Si$_{2}$ Sb$_{2}$ Te$_{5}$ and RMS roughness as a function of CF$_{4}$ /Ar gas mixture ratio.
DownLoad:
| Citation: |
Juntao Li, Bo Liu, Zhitang Song, Dongning Yao, Gaoming Feng, Aodong He, Cheng Peng, Songlin Feng. Reactive ion etching of Si2Sb2Te5 in CF4/Ar plasma for a nonvolatile phase-change memory device[J]. Journal of Semiconductors, 2013, 34(5): 056001. doi: 10.1088/1674-4926/34/5/056001
****
J T Li, B Liu, Z T Song, D N Yao, G M Feng, A D He, C Peng, S L Feng. Reactive ion etching of Si2Sb2Te5 in CF4/Ar plasma for a nonvolatile phase-change memory device[J]. J. Semicond., 2013, 34(5): 056001. doi: 10.1088/1674-4926/34/5/056001.
|
Reactive ion etching of Si2Sb2Te5 in CF4/Ar plasma for a nonvolatile phase-change memory device
DOI: 10.1088/1674-4926/34/5/056001
More Information
-
Abstract
Phase change random access memory (PCRAM) is one of the best candidates for next generation non-volatile memory, and phase change Si2Sb2Te5 material is expected to be a promising material for PCRAM. In the fabrication of phase change random access memories, the etching process is a critical step. In this paper, the etching characteristics of Si2Sb2Te5 films were studied with a CF4/Ar gas mixture using a reactive ion etching system. We observed a monotonic decrease in etch rate with decreasing CF4 concentration, meanwhile, Ar concentration went up and smoother etched surfaces were obtained. It proves that CF4 determines the etch rate while Ar plays an important role in defining the smoothness of the etched surface and sidewall edge acuity. Compared with Ge2Sb2Te5, it is found that Si2Sb2Te5 has a greater etch rate. Etching characteristics of Si2Sb2Te5 as a function of power and pressure were also studied. The smoothest surfaces and most vertical sidewalls were achieved using a CF4/Ar gas mixture ratio of 10/40, a background pressure of 40 mTorr, and power of 200 W.-
Keywords:
- reactive ion etching,
- phase-change material,
- Si2Sb2Te5
-
References
[1] Lam C H. Storage class memory. Solid-State and Integrated Circuit Technology, 2010 http://researcher.watson.ibm.com/researcher/view_group.php?id=3631[2] Annunziata R, Zuliani P, Borghi M, et al. Phase change memory technology for embedded non volatile memory applications for 90 nm and beyond. IEEE International Electron Devices Meeting, Technical Digest, 2009[3] Kim I S, Cho S L, Im D H, et al. High performance PRAM cell scalable to sub-20nm technology with below 4F2 cell size. Digest of Technical Papers, Symposium on Extendable to DRAM Applications in VLSI Technology, 2010 http://www.sciencedirect.com/science/article/pii/S0038110117300357[4] Kojima R, Okabayashi S, Kashihara T, et al. Nitrogen doping effect on phase change optical disks. Jpn J Appl Phys, 1998, 37:2098 doi: 10.1143/JJAP.37.2098[5] Liu Y B, Zhang T, Niu X M, et al. Si2Sb2Te5 phase change material studied by an atomic force microscope nano-tip. Journal of Semiconductors, 2009, 30(6):063003 doi: 10.1088/1674-4926/30/6/063003[6] Kojima R, Yamada N. Acceleration of crystallization speed by Sn addition to Ge-Sb-Te phase-change recording material. Jpn J Appl Phys, 2001, 40:5930 doi: 10.1143/JJAP.40.5930[7] Zhang T, Song Z T, Liu B, et al. Investigation of phase change Si2Sb2Te5 material and its application in chalcogenide random access memory. Solid-State Electron, 2007, 51:950 doi: 10.1016/j.sse.2007.03.016[8] Chinoy P B. Reactive ion etching of benzocyclobutene polymer films. IEEE Trans Components, Parking, and Manufacturing Technology, Part C, 1997, 20(3):99[9] Abe H, Yoneda M, Fujiwara N. Developments of plasma etching technology for fabricating semiconductor devices. Jpn J Appl Phys, 2008, 47:1435 doi: 10.1143/JJAP.47.1435[10] Plank N O V, Cheung R. Functionalization of carbon nanotubes for molecular electronics. Microelectron Eng, 2004, 73/74:578 doi: 10.1016/S0167-9317(04)00142-X[11] Feng G M, Liu B, Song Z T, et al. Reactive-ion etching of Ge2Sb2Te5 in CF4/Ar plasma for non-volatile phase-change memories. Microelectron Eng, 2008, 85(8):1699 doi: 10.1016/j.mee.2008.04.036[12] Sheridan T E, Goree J. Collisional plasma sheath model. Phys Fluids B, 1991, 3(10):2796 doi: 10.1063/1.859987[13] Knizikevicius R, Kopustinskas V. Influence of temperature on the etching rate of SiO2 in CF4 + O2 plasma. Microelectron Eng, 2006, 83(2):193 doi: 10.1016/j.mee.2005.08.004[14] Wolf R, Helbig R. Reactive ion etching of 6H-SiC in SF6/O2 and CF4/O2 with N2 additive for device fabrication. J Electrochem Soc, 1996, 143:1037 doi: 10.1149/1.1836578 -
Proportional views
