1. ©Syarifah Norfaezah 06/07 CHAPTER 1: INTRODUCTION Semiconductor Devices

2. ©Syarifah Norfaezah 06/07 What is Semiconductors? Semiconductors are materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most ceramics). Semiconductors can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide Ability to conduct electrical current, and they can be regulated in the amount of their conductivity. Si is most widely used – easily obtained. Early developments semiconductor – 1600 to 1800.

3. ©Syarifah Norfaezah 06/07 1947 – First Transistor, AT & T Bells Labs. 1952 – First Single Crystal Ge. 1954 – First Single Crystal Si. 1958 – First IC Device. 1961 – First IC Product, Fairchild Camera 1971 – Intel Microprocessor 1975 – First Personal Computer. 1981 – IBM Personal Computer. Semiconductor Era

4. ©Syarifah Norfaezah 06/07 Semiconductor Devices Applied Physics, E & E Eng, Materials Science. Semiconductor Devices – foundation of electronic industry. Largest industry in the world - >> USD trillion, since 1998. Fundamental study of devices (semiconductor physics) – to understanding the advanced course in electronics.

5. ©Syarifah Norfaezah 06/07 The first electronic digital computer was built in the basement of the physics department at Iowa State University in 1939 by Physicist, Professor Dr. John Atasanoff Tim Berners-Lee, a Physicist from CERN Particle Physics Lab, invented the World Wide Web in 1990 The underlying theory of photons which made the invention of the laser possible was first developed by Albert Einstein in 1905 1954 the first microwave laser was built by physicist Charles Townes. The first optical laser was built in 1960 by physicist Theodore Maiman

6. ©Syarifah Norfaezah 06/07 Semiconductor Devices (cont.) 1980199020002010 10 1 10 3 10 4 10 5 10 2 USD billion Year semiconductor steel electronics automobile Gross world product (GWP)

7. ©Syarifah Norfaezah 06/07 1.1Basic Devices Building Blocks MS/C MS/C AS/C B p – type S/C n – type S/C S/C oxide (1) Metal – semiconductor interface(2) p – n junction (3) Heterojunction interface(4) Metal – oxide semiconductor structure Semiconductor Devices (cont.)

8. ©Syarifah Norfaezah 06/07 1.Metal-semiconductor interface - intimate contact between a metal and a semiconductor - first semiconductor device ever studied (1874). -used as rectifying contact. -MESFET. 2.p-n junction - form between p-type s/c and n-type s/c. - key building block for most s/c devices. -p-n junction theory – foundation of the physics of s/c. -p-n-p bipolar transistor (1947). -p-n-p-n called thyristor. Semiconductor Devices (cont.)

9. ©Syarifah Norfaezah 06/07 3.Heterojunction interface - interface between two dissimilar s/c, i.e GaAs + AlAs  heterojunction. -the key components for high-speed and photonic devices. 4.Metal-Oxide-Semiconductor (MOS) structure -a combination of metal-oxide interface and oxide- semiconductor interface. - MOSFET (MOS field-effect transistor) – most important device for advanced IC. Semiconductor Devices (cont.)

10. ©Syarifah Norfaezah 06/07 1.2Major Semiconductor Devices YearSemiconductor DeviceInventor(s) 1874Metal-semiconductor contactBraun 1907Light emitting diode (LED)Round 1947Bipolar transistorBardeen, Brattain, Shockley 1949p-n junctionShockley 1954Solar cellChapin, Fuller, Pearson 1958Tunnel diodeLeo Esaki Semiconductor Devices (cont.)

11. ©Syarifah Norfaezah 06/07 YearSemiconductor DeviceInventor(s) 1962LaserHall et al. 1965IMPATT diodeJohnston, DeLoach, Cohen 1966MESFETMead 1967Nonvolatile s/c memoryKahng, Sze 1980MODFETMimura et al. 200120nm MOSFETChau 1.2Major Semiconductor Devices (cont.) Semiconductor Devices (cont.)

12. ©Syarifah Norfaezah 06/07 Semiconductor Technology YearTechnologyInventor(s) 1918Czochralski crystal growthCzochralski 1925Bridgman crystal growthBridgman 1952DiffusionPfann 1959Hybrid ICKilby 1963CMOSWanlass and Sah 1967DRAMDennard 1969MOCVDManasevit and Simpson 1971Dry EtchingIrving, Lemons, and Bobos 1971Microprocessor (4004)Hoff et al. 1993Copper interconnectParaszczak et al.

13. ©Syarifah Norfaezah 06/07 Semiconductor Tech. (cont.) As the complexity of the IC increased, we have move from NMOS (n-channel MOSFET) to CMOS (complementary MOSFET) technology – employs both NMOS and PMOS. CMOS technology is the dominant technology for advanced ICs. DRAM (dynamic random access memory) – the memory contains one MOSFET and one charge- storage capacitor. (MOSFET serve as switch to charge and discharge the capacitor).

14. ©Syarifah Norfaezah 06/07 Technology Trends The minimum length of IC has been reduced at rate about 13% per year. Device miniaturization also reduces the energy used for each switching operation. (energy has decreased over one million times since 1959). At the beginning of the modern technology era (1950 – 1970), bipolar transistor was the technology driver. 1970-1990, DRAM and the microprocessor based on MOS devices were the technology drivers (rapid growth of PC and advanced tech. systems. Since 1990, nonvolatile semiconductor memory has been the tech. driver – because of the rapid growth of portable electronic systems.

15. ©Syarifah Norfaezah 06/07 Summary Semiconductor Device field – new era of study – give a big impact to our society and the global economy (largest industry in the world – electronic industry). Started from metal-semiconductor contact in 1874 – to the fabrication of the ultrasmall 20nm MOSFET in 2001. Semiconductor devices: 1947 (Bipolar Transistor)  1960 (MOSFET)  1967 (invention of nonvolatile semiconductor memory). More than 300, 000 papers have been published in semiconductor-device physics field. Grand total may reach 1 million papers in the year 2012.

16. ©Syarifah Norfaezah 06/07 Next Chapter: Chapter 2 Energy Bands & Carrier Concentration in Thermal Equilibrium

17. ©Syarifah Norfaezah 06/07 “Try not to become a man of success but rather to become a man of value” Albert Einstein US (German-born) physicist (1879 - 1955)

18. ©Syarifah Norfaezah 06/07 “Education is the best provision for the journey to old age” Aristotle Greek critic, philosopher, physicist, & zoologist (384 BC - 322 BC)