1. (Introduction to Semiconductors) 1
* Semiconductor Semiconductor (Conductor) (Insulator) (Conductivity) Pentium chip, Memory chip, Transistor, Diode (Switch), (Rectification), (Amplification), (Charge storage), (Light emission), (Signal detection), (Calculation), (Memory) (, ) 2
* Semiconductor Semiconductor (Periodic table) 2 Element Semiconductor family Compound Semiconductor family family Ternary Quarternary GaN Si Ge SiC SiGe GaP GaAs InP CdSe ZnS ZnSe AlGaAs AlGaN HgCdTe AlGaAsP InGaAsP InSb 3
주기 1 2 토금속족 1 2 3 4 5 6 7 8 1 H 수소 1.00 3 Li 리듐 6.94 3 11Na 나트륨 22.99 4 5 6 7 족 알칼리알칼리금속족붕소족탄소족질소족산소족 19 K 칼륨 39.09 37 Rb 루비듐 85.47 55 Cs 세슘 132.91 87 Fr 프랑슘 (223) 4 Be 베릴륨 9.01 12 Mg 마그네슘 24.31 20 Ca 칼슘 40.08 38 Sr 스트론튬 87.62 56 Ba 바륨 137.33 88 Ra 라듐 (226) 21 Sc 스칸듐 44.96 39 Y 이트륨 88.91 57 La 란탄늄 138.91 89 Ac 악티늄 (227) 비금속 경금속 중금속 22 Ti 티타늄 47.88 40 Zr 지르코늄 91.22 72 Hf 하프늄 178.49 란탄족 23 V 바나듐 50.94 41 Nb 니오비듐 92.91 73 Ta 탄탈늄 180.95 24 Cr 크롬 51.99 42 Mo 몰리브덴 95.94 74 W 텅스텐 183.84 25 Mn 망간 54.94 43 Tc 테크네튬 (98) 75 Re 레늄 186.21 원자번호 26 Fe 철 55.85 44 Ru 루테늄 101.07 76 Os 오스뮴 190.23 27 Co 코발트 58.93 45 Rh 로듐 102.91 77 Ir 이리듐 192.22 1 H 수소 1.00 28 Ni 니켈 58.96 46 Pd 팔라듐 106.42 78 Pt 백금 195.08 원소기호원소이름원자량 29 Cu 구리 63.55 47 Ag 은 107.87 79 Au 금 196.97 30 Zn 아연 65.39 48 Cd 카드뮴 112.41 80 Hg 수은 200.59 5 B 붕소 10.81 13 Al 알루미늄 26.98 31 Ga 갈륨 69.72 49 In 인듐 114.88 81 Tl 탈륨 204.38 6 C 탄소 12.01 14 Si 실리콘 28.09 32 Ge 게르마늄 72.61 50 Sn 주석 118.71 82 Pb 납 207.20 7 N 질소 14.00 15 P 인 30.97 33 As 비소 74.92 51 Sb 안티몬 127.76 83 Bi 비스무스 208.98 8 O 산소 15.99 16 S 황 32.07 34 Se 셀레늄 78.96 52 Te 텔루르 127.60 84 Po 폴로늄 (209) 할로겐족 9 F 불소 19.99 17 Cl 염소 35.45 35 Br 브롬 79.90 53 I 요오드 126.90 85 At 아스타틴 (210) 휘발성기체족 2 He 헬륨 4.00 10 Ne 네온 20.18 18 Ar 아르곤 39.95 36 Kr 크립톤 83.80 54 Xe 크세논 131.29 86 Rn 라돈 (222) 악티늄족 58 Ce 세륨 140.12 90 Th 토륨 232.04 Pr 59 프리세오디뮴 140.91 Pa 91 프로악티늄 (231) 60 Nd 네오디뮴 144.24 92 U 우리늄 238.03 61 Pm 프로메튬 (145) 93 Np 넵투늄 (237) 62 Sm 사마륨 150.36 94 Pu 플루토늄 (244) 63 Eu 유로퓸 151.97 95 Am 아메리슘 (243) 64 Gd 가들리늄 157.25 96 Cm 퀴륨 (247) 65 Tb 테르븀 158.93 97 Bk 버클륨 (247) Dy 66 디스프로슘 162.50 Cf 98 칼리포르늄 (251) 67 Ho 홀륨 168.93 99 Es 아인시타이늄 (252) 68 Er 에르븀 167.26 100Fm 페르뮴 (257) 69 Tm 툴륨 168.93 101Md 멘델레븀 (258) 70 Yb 이테르븀 173.04 102No 노벨륨 (259) 71 Lu 루테륨 174.97 103 Lr 로렌슘 (260) 4
11. 1. (Atomic structure) (Atom) All matter is made of atoms.. All atoms are made of nucleus and electrons. ( ). The nucleus consists of positively charged particles called protons and uncharged particles called neutrons.. Nucleus Proton(+) Neutron() Electron() Figure 11. The Bohr model of an atom. 5
11. 1. (Atomic structure) Nucleus with 1 proton Nucleus with 2 protons and 2 neutrons. 1 electron orbiting the nucleus 2 electrons orbiting the nucleus (a) Hydrogen atom (b) Helium atom Figure 12. The simplest atoms, hydrogen and helium. (Atomic number) All elements arranged in the periodic table of the elements in order according to their atomic number. (Element). The atomic number equals the number of protons in the nucleus, which is the same as the number of electrons in an electrically balanced(neutral) atom.,. 6
11. 1. (Atomic structure) (The periodic table of the elements) <= >, < = ( ) > 7
11. 1. (Atomic structure) (Electron orbits) Electrons orbit the nucleus of an atom at certain distances from the nucleus.. Electrons near the nucleus have less energy than those in more distant orbits..( ) It is known that only discrete(separate and distinct) values of electron energies exist within atomic structures.. Figure 13. The electron orbit. 8
11. 1. (Atomic structure),, (Energy levels, Energy bands & Shells) (micro) (particle) Each discrete distance(orbit) from the nucleus corresponds to a certain energy level.. In an atom, the orbits are grouped into energy bands known as shells.,. A given atom has a fixed number of shells.. Each shell has a fixed maximum number of electrons at permissible energy levels.. The shells are designated K, L, M, N, and so on, K, L, M, N,. Energy level 3 2 1 Nucleus K shell L shell 9
11. 1. (Atomic structure) (Principal quantum number) n n = 1, 2, 3, (Orbital quantum number) 0 n 1 (Magnetic quantum number) m m (Spin quantum number) s 1/2, +1/2 Shell Quantum number ( ) n m s K 1 0 0 ±1/2 1s 2 L 2 M 3 0 0 ±1/2 2s 2 1 1 0 +1 ±1/2 ±1/2 ±1/2 2p 6 0 0 ±1/2 3s 2 1 1 0 +1 ±1/2 ±1/2 ±1/2 3p 6 2 2~+2 ±1/2 3d 10 n=1, =0 n=2, =0 n=2, =1 n=3, =1 n=3, =0 n=3, =2 10
11. 1. (Atomic structure) C( ) 6 1s(2) 2s(2) 2p(2) K L Energy level 3 2 2p L 1 K 2s 1s K K shell L shell L Nucleus 11
11. 1. (Atomic structure) (Valence Electrons) Electrons that are in orbits farther from the nucleus have higher energy and are less tightly bound to the atom than those closer to the nucleus. ( ),. This is because the force of attraction between the positively charged nucleus and the negatively charged electron decreases with increasing distance from the nucleus. (+) ().( ) Electrons with the highest energy levels exist in the outermost shell of an atom and are relatively loosely bound to the atom.,. The outermost shell is known as the valence shell and electrons in this shell are called valence electrons., ( ). 12
11. 1. (Atomic structure) These valence electrons contribute to chemical reactions and bonding within the structure of a material and determine its electrical properties.,. Na( ) : 11 : 1s(2) 2s(2) 2p(6) 3s(1) Cl() : 17 : 1s(2) 2s(2) 2p(6) 3s(2) 3p(5) Valence shell ( ) + + K K L Valence electron L M M ( ) 13
11. 1. (Atomic structure) (Ionization) When an atom absorbs energy from a heat source or from light, for example, the energy levels of the electrons are raised.,,. The valence electrons possess more energy and are more loosely bound to the atom than inner electrons, so they can easily jump to higher orbits within the valence shell when external energy is absorbed.,.. If a valence electron acquires a sufficient amount of energy, it can actually escape from the outer shell and the atom s influence.,,. 14
11. 1. (Atomic structure) The process of losing a valence electron is known as ionization, and the resulting positively charged (more protons than electrons) atom is called a positive ion., (+). The escaped valence electron is called a free electron.. When a free electron loses energy and falls into the outer shell of a neutral atom, the atom becomes negatively charged (more electrons than protons) and is called a negative ion., (),. Energy + + + + + + + + + + + + Energy 15
11. 1. (Atomic structure) 8(Octet rule) 8 8.< Octet > Na Cl + K + K L M L M Na Na(+1) + e(1) Cl + e(1) Cl(1) 16