Transient phase change effect in phase change memory devices

Yeo, Eng Guan

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https://hdl.handle.net/2142/18640 Copy

Description

Title

Transient phase change effect in phase change memory devices

Author(s)

Yeo, Eng Guan

Issue Date

2011-01-21T22:52:48Z

Director of Research (if dissertation) or Advisor (if thesis)

Adesida, Ilesanmi

Doctoral Committee Chair(s)

Adesida, Ilesanmi

Committee Member(s)

• Jain, Kanti
• Kim, Kyekyoon
• Bishop, Stephen G.

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• phase change memory
• Phase change random access memory (PCRAM)
• transient effect
• time-resolved
• filament

Abstract

Phase change random access memory (PCRAM) is a leading contender for next generation nonvolatile memory. The phase change mechanism from high resistance amorphous phase to low resistance crystalline phase in nano-timescale is the most important characteristic of these materials. However, full understanding of the mechanism is still not achieved. Two time parameters were identified from the transient waveform, namely the delay and current recovery times. The link between crystallization kinetics and the transient phase change effect was established by associating nucleation with delay time and growth with current recovery time. Real-time crystallization characterization was achieved. Parasitic capacitance had strong implications on the programming performance of PCRAM. Larger parasitic capacitance results in a larger leakage current, and hence higher applied voltage for RESET operation needs to be applied. The larger parasitic capacitance also results in an increased quenching time due to a longer voltage fall time, which results in a partially crystallized amorphous state. Continuing work is studying the effect of filament formation on phase change. Filament formation is linked to the actual operating performance of the PCRAM device. This link is important in understanding how phase change occurs electrically and whether filament formation has any effect on scaling of PCRAM devices.

Graduation Semester

2010-12

Permalink

http://hdl.handle.net/2142/18640

Copyright and License Information

Copyright 2010 Eng Guan Yeo

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