A Tutorial Introduction to Negative-­Capacitor Landau Transistors: Perspectives on the Road Ahead

By Muhammad A. Alam

Electrical and Computer Engineering, Purdue University, West Lafayette, IN

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Abstract

This is the fifth in a series of talks on device options and trade-offs for the 5 nm node. Negative Capacitor Field Effect Transistors (NC-FETs) promise to sustain Moore’s law by reducing the supply voltage (and thereby, self-heating) below the lowest limit achievable by classical transistors. Conceptually, the reduction in voltage is achieved by integrating a negative capacitor in the gate-stack; the internal voltage amplification turns a transistor on and off at voltages much lower that previously thought possible. Unfortunately, the notion of a “negative capacitor”, the debate regarding experimental demonstrations, apparent disconnect with equations of classical transistors, etc. make the NC-FET a mysterious and hard-to-understand addition to the device literature. In this talk, I use a simple graphical approach to demystify the device and explain why the experimental results are easy to misinterpret. Since the NC-FET is just a special case of a much broader class of phase-change devices and systems (e.g., transistors, memories, MEMS, logic-in-memory architecture) that operate by tailoring the Landau potential energy landscape, once NC-FET is understood, the operation of all other devices becomes intuitively obvious as well. The talk will conclude with a discussion of four possible roads to improving NC-FET device performance.

A MATLAB script that implements the concepts discussed in this tutorial is also available as is a list of resources for Landau switches.

Bio

Muhammad A. Alam Professor Alam is the Jai N. Gupta Professor of Electrical Engineering at Purdue University where his research focuses on fundamental limits of classical and emerging electronic devices. Before joining Purdue in 2004, Prof. Alam spent a decade in Bell Labs and Agere systems where he made important contributions to reliability physics of transistors and design of optoelectonic integrated circuits. He has published more than 200 papers, presented numerous invited and contributed talks, and more than 100,000 students have learned some aspect of semiconductor devices from his web-based lectures. He is a fellow of IEEE, APS, and AAAS, and recipient of 2006 IEEE Kiyo Tomiyasu Award and 2015 SRC Technical Excellence Award for contributions to device technology for communication systems.

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Cite this work

Researchers should cite this work as follows:

  • Muhammad A. Alam (2015), "A Tutorial Introduction to Negative-­Capacitor Landau Transistors: Perspectives on the Road Ahead," https://nanohub.org/resources/23157.

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Time

Location

121 Burton Morgan, Purdue University, West Lafayette, IN

Tags

A Tutorial Introduction to Negative-­Capacitor Landau Transistors: Perspectives on the Road Ahead
  • A Tutorial Introduction to Negative Capacitor Field Effect Transistors: Perspective on The Road Ahead Muhammad A. Alam alam@purdue.edu 1. A Tutorial Introduction to Neg… 0
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  • Acknowledgment 2. Acknowledgment 73.907240573907245
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  • Outline 3. Outline 103.53687020353688
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  • Motivation: Power dissipation 4. Motivation: Power dissipation 157.92459125792459
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  • Power vs. self-heating 5. Power vs. self-heating 240.74074074074076
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  • Outline 6. Outline 413.01301301301305
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  • Classical MOSFET: Band diagram 7. Classical MOSFET: Band diagram 431.93193193193196
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  • Capacitors control MOSFET Operation 8. Capacitors control MOSFET Oper… 597.59759759759766
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  • S for classical transistors 9. S for classical transistors 651.28461795128464
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  • Phase Space of MOSFET 10. Phase Space of MOSFET 791.65832499165833
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  • I-V Characteristics of a MOSFET 11. I-V Characteristics of a MOSFE… 920.52052052052056
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  • Recall: Capacitor divider rule 12. Recall: Capacitor divider rule 983.983983983984
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  • Graphical approach to S: Classical FET 13. Graphical approach to S: Class… 1128.7620954287622
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  • Graphical approach to S: NC-FET 14. Graphical approach to S: NC-FE… 1272.1054387721056
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  • Outline 15. Outline 1380.1134467801135
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  • A short history of positive capacitors 16. A short history of positive ca… 1398.9656322989656
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  • A capacitor minimizes stored energy 17. A capacitor minimizes stored e… 1491.9919919919921
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  • Landscape defines the sign of a capacitor 18. Landscape defines the sign of … 1568.2015348682016
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  • Positive and Negative Capacitors 19. Positive and Negative Capacito… 1736.8034701368035
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  • Types of NC 20. Types of NC 1850.8842175508844
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  • Charge, Field, Potential of Capacitors 21. Charge, Field, Potential of Ca… 1969.4694694694695
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  • Classical vs. NC-MOSFET 22. Classical vs. NC-MOSFET 2095.3953953953956
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  • IF we had a constant NC-FET … 23. IF we had a constant NC-FET   2214.1808475141811
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  • … I-V would be easily calculated 24. … I-V would be easily calcul… 2232.7994661327994
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  • Outline 25. Outline 2305.9059059059059
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  • FE is a voltage dependent NC 26. FE is a voltage dependent NC 2343.8104771438107
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  • FE-FET improves 0<S<60, but … 27. FE-FET improves 0 2384.4511177844511
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  • MOS Capacitor is nonlinear as well! 28. MOS Capacitor is nonlinear as … 2463.12979646313
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  • Real FE-FET with 0<S<60 29. Real FE-FET with 0 2521.5882549215885
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  • Minimum S for different FE 30. Minimum S for different FE 2577.1438104771437
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  • S improves for all these transistors 31. S improves for all these trans… 2608.0747414080747
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  • Outline 32. Outline 2644.8448448448448
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  • Strategies to improve S 33. Strategies to improve S 2679.1124457791125
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  • Approach 1: Stack of Negative Capacitor 34. Approach 1: Stack of Negative … 2803.2365699032366
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  • Proposed NEM-FE FET 35. Proposed NEM-FE FET 2858.7253920587254
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  • Physics of Zero-subthreshold slope 36. Physics of Zero-subthreshold s… 2900.8341675008342
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  • Capacitance of a FE-AFE FET 37. Capacitance of a FE-AFE FET 3010.9442776109445
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  • FE-AFE FET 38. FE-AFE FET 3075.5422088755422
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  • Approach 2: Use Overlap Capacitors 39. Approach 2: Use Overlap Capaci… 3110.2769436102772
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  • Approach 3: Tailor Coefficients by Geometry 40. Approach 3: Tailor Coefficient… 3172.0387053720387
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  • Approach 3: Tailor Coefficients by Geometry 41. Approach 3: Tailor Coefficient… 3190.156823490157
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  • Induced NC 42. Induced NC 3250.4170837504171
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  • Outline 43. Outline 3284.3510176843511
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  • Capacitor 44. Capacitor 3311.4114114114113
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  • Recall: Essence of Negative Capacitor 45. Recall: Essence of Negative Ca… 3346.27961294628
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  • Ion Motion and Transient NC 46. Ion Motion and Transient NC 3394.9949949949951
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  • Ion Motion and Transient NC 47. Ion Motion and Transient NC 3559.2926259592928
    00:00/00:00
  • Switching & Reliability of Ferroelectrics 48. Switching & Reliability of Fer… 3643.7103770437107
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  • Coercive Voltage Dependence 49. Coercive Voltage Dependence 3732.2989656322993
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  • Theoretical Model (cont.) 50. Theoretical Model (cont.) 3787.253920587254
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  • Untitled: Slide 51 51. Untitled: Slide 51 3826.7600934267602
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  • Experimental Verification 52. Experimental Verification 3887.6543209876545
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  • Conclusions 53. Conclusions 3921.988655321989
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  • Resources 54. Resources 4100.4337671004341
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  • For Further Reading: NC in Transistors 55. For Further Reading: NC in Tra… 4127.2939606272939
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