Vijay K. Arora Wilkes University E-mail: varora@wilkes

1. Vijay K. Arora Wilkes University E-mail: varora@wilkes.edu

2. Emerging Technologies

3. Our Motivation and Economics Adam Smith, “An Enquiry into Nature and Causes of the Wealth of Nations” (1776) The wealth is created by laisse-faire economy and free trade John Maynard Keynes, “The General Theory of Employment, Interest, and Money” (1936) The wealth is created by careful government planning and government stimulation of economy 1990’s and Beyond The wealth is created by innovations and inventions

4. 20th Century Paradigm • Formulate a hypothesis or theory • Accumulate data • Do extensive experimentation and Check • Publish if newsworthy • Respect others’ work helping them to grow in the profession • Demonstrate character ethics that puts community interests above personal aggrandizement

5. 21st Century Paradigm • Formulate a hypothesis or theory or design • Make a prototype structure • Patent it • Raise 17 million dollars and start an IPO • Sue your competitor for stealing your idea • Demonstrate personality ethics that lubricates the process of human interaction for personal aggrandizement

6. Gross world product and sales volumes

7. Exponential GrowthSIA roadmap

8. Historical Trends • New Technology generation every three years • For each generation, memory density increase by 4 times and logic density increases by 2.5 times • Rule of Two: In every two generations (6 years), the feature size decreased by 2, transistor current density, circuit speed, chip area, chip current and maximum I/O pins increased by 2

9. Research Scenario • A comprehensive transport theory for quantum processes at nanosacle • High-field distribution in quantum wells • Optimization of the shape and size of quantum wells for high frequencies • Quantum Computing: Multi-state logic by using quantum states • Failure of Ohm’s Law: Re-assessment of the circuit theory principles

10. Goals for High Speed Performance • Large transistor current • Time constants • Interconnects • Cross talk • Reduced transit time • Increased Mobility • High Saturation Velocity • Reduced Size

11. Source: Cadence RC and Transit Time Delays Source: Cadence

12. Interconnect ProblemsRC Time Delays • RC time delay is increasing rapidly • Wire resistance is rising • Wires have larger cross-section … introduce coupling • Electromigration imposes current limits • System performance, area and reliability are determined by interconnect quality, not devices!!!

13. 1  0.5  Increasing Performance Decreasing Coupling Effect Interconnect Performance 0.25  Increased cross-section improves performance but also increases noise and capacitive and inductive coupling

14. R3 R2 R1 layer m Cc layer m Cf Cf Cf Co Cf Cs Cf Cf Cs Cf Cf substrate R4 layer n RC Delay Considerations • Cint = Cf + Cs + Co + Cload •  = Rint * ( Cint + Cc/(Cint+ Cc) ) •  = Rint * (Cint2 + Cint.Cc +Cc)/(Cint + Cc) • Cc depends on dimensional shrink due to increased in cross-section • In VLSI, make Cc becomes insignificant as possible, then •  = Rint * Cint

15. Physical Effects • Quantum Effects • High-Field Effects • Field Broadening

16. Nano-Scale Quantum Engineering

17. Bulk Semiconductors All 3 cartesian directions analog-type Density of States:

18. Quasi-Two-Dimensional QW z-direction digital-type x,y-directions analog-type Density of States:

19. AlGaAs/GaAs/AlGaAs Prototype Quantum Well

20. Quasi-One-Dimensional QW y, z-direction digital-type x-directions analog-type (QWW) Density of States:

21. Quasi-Zero-DimensionalQuantum Well All 3 cartesian directions digital-type Quantum box (dot)

22. Quantum Well WireQuantum Box (Dot)

23. Quantum Well Arrays

24. Density of States

25. Quantum Well with Finite Boundaries

26. Triangular Quantum Well Approximate: Exact:

27. Quantum-Confined Mobility Degradation • Changes in the Density of States • Changes in the relative strength of each scattering interaction

28. Mobility Degradation Versus Quantum Confinement

29. Gate-Field ConfinementMobility Degradation in a TQW

30. Electron and Hole Mobility in Submicron CMOS Courtesy: Y. Taur and E. Novak, IBM Microelectronics, IEDM97 Invited Talk.

31. Random Thermal Motion

32. Quantum Emission

33. Randomness to Streamlining Velocity Vectors in Equilibrium Randomness: Velocity Vectors in a Very High Field Streamlined:

34. Saturation Velocity-Bulk Fermi Integral Normalized Fermi Energy

35. Saturation Velocity Limits Non-degenerate limit Degenerate limit

36. Saturation Velocity-Q2D

37. Saturation Velocity-Q1D

38. Modeling Transport =0 Transient Response:

39. Quantum Emission Effective Collision time: Effective collision length:

40. 1-D Random Walk in a Bandgap semiconductor

41. Modeling the Distribution

42. Left-Right AsymmetryItinerant Electron Population

43. Streamlining the Randomness

44. Drift-Diffusion Drift Diffusion Drift Velocity Diffusion Coefficient

45. Single-Valley v-E Characteristics

46. Velocity-Field Characterisitcs

47. Effect of Degeneracy (2-D)

48. Mobility Degradation

49. Diffusion Coefficient Degradation

50. I-V Characteristics Microresistors