Semiconductors: Fundamentals, Materials, Doping, History, and Industry Overview

Semiconductors

Fundamentals, Materials, Doping, History, and Industry Overview

---

Photo by Igor Shalyminov on Unsplash

• What are Semiconductors?
• Common Materials
• Doping Process
• n-type vs p-type Semiconductors
• Historical Milestones
• Pioneer Companies
• Industry Statistics
• Key Applications & Conclusion

---

Photo by L N on Unsplash

1

What are Semiconductors?

Materials with conductivity between conductors and insulators

---

Photo by Vedrana Filipović on Unsplash

• Material with electrical conductivity between conductor (e.g., metals) and insulator (e.g., glass)
• Conductivity modified by 'doping' - adding impurities to crystal structure
• Two differently doped regions form a semiconductor junction
• Basis for diodes, transistors, and most modern electronics
• Sometimes refers to devices like microchips and processors

• Silicon: Most common, basis for most electronic circuits
• Germanium: Early semiconductor
• Gallium Arsenide: 2nd most common; laser diodes, solar cells, microwave ICs
• Others: Elements near 'metalloid staircase' on periodic table

---

Photo by Igor Shalyminov on Unsplash

2

Doping Process

Adding impurities to control conductivity and create p-n junctions

---

Photo by Bill Xi on Unsplash

n-type Doping Group V impurities (antimony, phosphorus, arsenic) Act as donors, create free electrons Doping level: ~1 in 10^8 atoms Increases charge carriers

p-type Doping Group III impurities (boron, gallium, indium) Act as acceptors, create 'holes' Precise control of p-n regions for junctions Conductivity also rises with temperature (unlike metals)

1904: Cat's-Whisker Detector First practical semiconductor diode for radio receivers 1947: Transistor Invented Quantum physics enables Bell Labs' Shockley, Bardeen, Brattain 1955: Shockley Semiconductor Early company founded 1957: Fairchild Semiconductor Traitorous Eight defect from Shockley; pioneers ICs 1958: Integrated Circuit Independently invented by Kilby (TI) and Noyce (Fairchild)

• Fairchild Semiconductor (1957): Founded by 'Traitorous Eight' from Shockley Lab; pioneered transistors & ICs; acquired by ON Semi in 2016
• Shockley Semiconductor (1955): Early entrant
• Texas Instruments: Jack Kilby invented IC (1958)
• Others: Motorola (1952), Bell Labs (transistor 1947/48), Sylvania, Centralab

• $556B: 2021 Global Sales
• 1.15T: Units Shipped 2021
• $727B: Projected 2027
• $193B: China Sales 2021

---

Photo by Debagni Sarkhel on Unsplash

• Useful properties: One-way current, variable resistance, light/heat sensitivity
• Devices: Diodes, transistors, integrated circuits
• Applications: Amplification, switching, energy conversion (solar cells)
• Gallium arsenide: Laser diodes, microwave ICs
• Also: High-voltage cable insulation (XLPE with carbon black)

---

Photo by Robin Glauser on Unsplash

Semiconductors: Bridge between conductors & insulators Doped for p-n junctions enabling diodes, transistors, ICs Silicon dominant; industry sales hit $556B in 2021, heading to $727B by 2027 Pioneers like Fairchild drove transistor & IC revolutions

Essential foundation of modern electronics and future technologies

---

Photo by Hyunwon Jang on Unsplash