Unit-2_Electronic circuit and PCB d.pptx

ppts

1. ELECTRONIC SYSTEM AND PCB DESIGN(21ECC101J ) Unit-2 DR. AARTI Sharma Assistant professor Department of Ece SRM IST, Delhi ncr campus 1

2. Course outcome of Unit-2 At the end of this unit student will get to know about working principle and characteristics of special semiconductor devices. 2

3. Contents Introduction to power electronics, applications and role of power electronics Introduction to power semiconductor devices, Operating characteristics of Power Diodes, Gunn Diode, Schottky Diode, IMPATT Diode, Introduction to Thyristor, PNPN Diode Silicon Control Rectifier (SCR), Thyristor Rating, Physics of Power BJT and Switching Characteristics , Physics of Power MOSFET and Characteristics Monolithic Fabrication Process, Fabrication of Monolithic Diode, Fabrication of monolithic capacitors and resistors 3

4. 1. Power Electronics 4 Power electronics is a field of electrical engineering that deals with the conversion, control, and management of electrical energy. It plays a crucial role in modern electrical and electronic systems, enabling efficient energy transformation and control.

5. Role of Power Electronics in Modern Systems 5

6. Power Diodes 6

7. V-I Characteristics of Power Diode 7

8. Characteristics of Power Diode High Voltage Rating High Current Rating Low switching speed 8

9. GUNN Diode 9

10. GUNN Diode Gunn diodes are also known as transferred electron devices(TED) are widely used in microwave RF applications for frequencies between 1 and 100 GHz. Gallium Arsenide Gunn Diodes are made for frequencies up to 200GHz whereas Gallium Nitride can reach up to 3THz. •The Gunn diode is most commonly used for generating microwave RF signals - these circuits may also be called a transferred electron oscillator or TEO. 10

11. Construction The top and bottom areas of the device are heavily doped to give N+ material. The device is mounted on a conducting base to which a wire connection is made. It also acts as a heat-sink for the heat which is generated. The connection to the other terminal of the diode is made via a gold connection deposited onto the top surface. Gunn diodes are fabricated from a single piece of n-type semiconductor. The most common materials are gallium Arsenide, GaAs and Indium Phosphide, InP . However other materials including Ge, CdTe , InAs , InSb , ZnSe and others have been used. The device is simply an n-type bar with n+ contacts. It is necessary to use n-type material because the transferred electron effect is only applicable to electrons and not holes found in a p-type material. 11

12. Construction of Gunn Diode 12

13. 13

14. 2. Doping in Semiconductors 14

15. I n t r i ns i c s e m i co n d u c t or s An intrinsic semiconductor is one which is made of the semiconductor material in its extremely pure form. Examples : Si, Ge The energy gap is so small that even at ordinary room temperature; there are many electrons which possess sufficient energy to jump across the small energy gap between the valence and the conduction bands. Alternatively, an intrinsic semiconductor may be defined as one in which the number of conduction electrons is equal to the number of holes. 15

16. Fermi Energy and Fermi Level Fermi Energy It is the maximum energy possessed by free electron at absolute zero temperature. Fermi level It is the highest energy state occupied by free electron at absolute zero temperature. 16

17. Fermi Level 17

18. Conductivity of Semiconductor 18 Where σ is the conductivity of the semiconductor .

19. Fermi Dirac Function Fermi Dirac Distribution is the probability distribution function which states the probability of finding an electron in the given energy level. 19

20. Explanation 20

21. Carrier Concentration in Intrinsic semiconductor 21 In Intrinsic semiconductor when the valence electron broke covalent bond and jump into conduction band two types of charge carriers are generated. They are electrons and holes. Intrinsic carrier concentration The number of electron per unit volume in conduction band or number of holes per unit volume in valence band is called intrinsic carrier concentration.

22. Mass Action Law 22

23. Drift Current 23 The current flow in semiconductor under the influence of electric field is called drift current.

24. Diffusion Current The current flow in semiconductor from region of higher concentration to the lower concentration is called diffusion current. 24

25. Einstein Relationship The equation which relates the mobility and the diffusion constant is known as Einstein relationship. 25

26. P-N Junction Diode 26

27. 27

28. 28

29. 29

30. 30

31. BJT Configurations 31

32. MOSFET 32

33. D-MOSFET 33

34. Enhancement type MOSFET 34

35. Double Gate MOSFET 35

36. Construction of Dual Gate MOSFET 36

37. Working of Dual Gate MOSFET 37

38. V-I Characteristic of Dual Gate MOSFET 38

39. Advantages of Dual Gate MOSFET 1) Reduced channel and gate leakage current at off state which saves power. 2 ) Separate gate control on voltage saves power and chip area. 39

40. Challenges in Dual Gate MOSFET 1) Identically sized gates 2) Self alignment of source and drain to both gates 3) Alignment of both gates to each other 4) Connecting two gates with low resistance path 40

41. Applications of Dual Gate MOSFET 1) Mixers 2) Demodulators 3) Cascade amplifiers 4) Radio Frequency (RF) amplifier 5) Automatic Gain Control (AGC) amplifier 41

42. Fin FET . 42

43. MOSFET Scaling . 43

44. Issues in Nano MOSFETs 44

45. Issues in Nano MOSFETs 45

46. Issues in Nano MOSFETs 46

47. 47

48. Planar MOSFET VS. Fin FET 48

49. Structure of Fin FET . 49

50. Classification of Fin FET 50

51. Short Gate (SG) and Insulated Gate (IG) FET 51

52. Short Gate (SG) vs. Insulated Gate (IG) FET 52

53. Short Gate (SG) and Insulated Gate (IG) FET 53

54. 54

55. Bulk Fin FET vs. SOI Fin FET 55

56. 56

57. 57

58. 58

59. 59

60. 60

61. Fabrication of Fin (Bulk Fin) 61

62. Fabrication of Fin (Bulk Fin) 62

63. 63

64. 64

65. 65

66. 66

67. Future of Fin FET 67