Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-23T17:43:46.899Z Has data issue: false hasContentIssue false

Investigation on Ultra-high Density and High Speed Non-volatile Phase Change Random Access Memory (PCRAM) by Material Engineering

Published online by Cambridge University Press:  01 February 2011

E.G. Yeo
Affiliation:
[email protected], Data Storage Institute, Optical Materials and Systems, DSI Building, 5 Engineering Drive 1, Singapore, Singapore, 117608, Singapore
L.P Shi
Affiliation:
[email protected], Data Storage Institute, 5 Engineering Drive 1, Singapore, Singapore, 117608, Singapore
R Zhao
Affiliation:
[email protected], Data Storage Institute, 5 Engineering Drive 1, Singapore, Singapore, 117608, Singapore
T.C. Chong
Affiliation:
[email protected], Data Storage Institute, 5 Engineering Drive 1, Singapore, Singapore, 117608, Singapore
Get access

Abstract

In this paper, ultra-high memory density and high speed non-volatile phase change random access memory (PCRAM) was investigated by material engineering. The melting point, crystallization point and activation energy of crystallization of the Bismuth (Bi) doped Germanium-Antimony-Tellurium (GeSbTe) compound was measured using differential scanning calorimetry (DSC) and compared to other GeSbTe ternary compounds. It was observed that the melting temperature of Bi-doped GeSbTe was lower than that of GeSbTe. On the other hand, its activation barrier was found to be reduced, which in turn increased the speed of crystallization of Bi-doped GeSbTe. Bi-doped GeSbTe was then used as a phase change material in the fabrication of PCRAM devices. The properties of PCRAM fabricated using this material were then compared to those using GeSbTe, with emphasis on the programming current required. The results obtained revealed that lower programming current of up to 40% has been achieved for PCRAM with Bi-doped GeSbTe compared to those with other GeSbTe compounds. Bi-doped GeSbTe also has low RESET current and fast speed of crystallization with scaling, making it a suitable material for high speed, ultra-high density PCRAM fabrication in the future.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Lai, SCurrent state of the phase change memory and its futureIntel Corp, USA Google Scholar
2. Hwang, Y.N., etc “Full Integration and Reliability Evaluation of Phase change RAM Based on 0.24um CMOS Technologies” Samsung Electronics 2003 Symposium on VLSI Technology Digest of Technical PapersGoogle Scholar
3.ITRS 2003 Emerging Research DevicesGoogle Scholar
4. Ha, Y.H., Yi, J.H., Horii, H., Park, J.H., Joo, S.H., Park, S.O., , U-InChung, Moon, J.T. “An Edge Contact Cell for Phase Change RAM Featuring Very Low Power Consumption” Samsung Electronics 2003 Symposium on VLSI Technology Digest of Technical PapersGoogle Scholar
5. Hwang, Y.N., etc “Novel Cell Structure of PRAM with Thin Metal Layer inserted GeSbTe” Samsung Electronics IEDM 2003 Google Scholar
6. Hosaka, S, Miyauchi, K, Tamura, T Proposal for a memory transistor using phase change and nanosize effects Science Direct, Gunma University, Japan Google Scholar
7.Ovonyx Technology Technical Presentation pg11 www.ovonyx.com/ovonyxtech.htmlGoogle Scholar
8. Lee, C.M., Chin, T.S., Huang, E.Y. Optical properties and structure of Te-Ge-Bi-Sb compounds with fast phase change capability Jpn. J. Appl. Phys Vol 89, No 6 (2001)Google Scholar
9. Lee, T.Y., Kim, K.B. Thin film alloy mixtures for high speed phase change optical storage: A study on (Ge1Sb2Te4)1-x(Sn1Bi2Te4)x Appl. Phys. Lett Vol 80, No 18 (2002)Google Scholar
10. Wang, K., Wamwangi, D., Zielger, S. Influence of Bi doping upon the phase change characteristics of Ge2Sb2Te5 Jap.J.Appl.Phys Vol 96 No 10 (2004)Google Scholar
11. Piovano, A., Lacaita, A.L., Hudgens, S. etc Scaling Analysis of Phase Change Technology IEDM03 pg 699702 Google Scholar
12. Kolobov, A, Fons.P etc Understanding the phase change mechanism of rewritable optical media Nature Oct 2004 Vol 3 Pg 703708 Google Scholar