반도체 소자 요약 - Hanyang Univ. NQE Lab.

1 Solid state electronic devices Introduction - : fundamental - : PN, Tr. (MOSFET & BJT), , solar cell, optical device, power device, logic, VLSI, etc. Contents Introduction Chap1: & solid state physics Chap2: level , Chap3: band carrier transport Chap4: Chap5~6: PN , MOSFET Chap7~10: application (BJT, , , ) Physics of semiconductor devices, Sze - PN junction (band diagram) (poisson s equation) , (bias) , ( & ) . (capacitance) : vs. 2.

2 - - (schottky) vs. (ohm) - (hetero-junction) p-n ; (rectifier) (forward bias) p n p n . (reverse bias) p n . p-n (voltage-variable) , , . p-n p-n Junction E . V0 (contact potential) , . 0.)()(0.)()( diffJdriftJdiffJdriftJnnpp p-n : (a) p n ; (b) W ; (c) 4 case Nd>Na p-n (a) x=0 (b) (c) E +x Approximation 0 ( ) , : A dnapNqAxNqAx00 adNNnpqdxxd )(E)0( ,)(E)0( ,)(E00 xxNqdxxdxxNqdxxdpand 000pandxNqxNq E WxNqWVnd0212100 E : dnapNxNx00 daanpnNNNWxxxW 000, 2021 WNNNNqVdada 2/102/10112 2 dadadaNNqVNNNNqVW.

3 P-n , , ( ), W (a) (b) (c) Forward- and reverse-biased junctions; steady state conditions Vf , V0 V0-Vf . (V=-Vr) .. q . [q(V0-Vf)] , [q(V0+Vf)] . n EFn EFp qVf EFp EFn qVr . (eV) (V) . / biased p-n (diffusion current) , p n p n.

4 (exponential ) (V0+Vr) n p . (exponential ) . (drift current) (space charge) (transition region) (built-in field) .. ( ) . - (EHP) . EHP . biased p-n n n .. n Lp . : (a) xn xp ; (b).

5 + V - (a) (b) biased p-n V exponential . kTqVexp p-n I-V = + p-n I-V |I( )| 0. |I( )|exp(qV/kT) . I=I0(eqV/kT-1) . eqV/kT 0 -I0 ( ) . p-n (a) . (b) . (c) p-n kTqVnpepp/ , p-n kTqVnnepxp/)(0 V0-V p(-xp0) = pp , kTVVqnpexpxp/)(000)()( (V>0) n p(xn0).

6 (V<0) p(xn0) pn . , 1)(1)(//00 kTqVppppkTqVnnnnennxnneppxppp-n Carrier injection pnpnnpnpLxkTqVnLxnnLxkTqVpLxppeepepxpeen enxn//////1)(1)( p n ( n p) . n xn 1)0(1)0()()()(/// kTqVppnpnnpnkTqVnppnppnpnppLxnppnnpnpenL qADnLDqAxIepLqADpLDqAxIxpLDqAepLDqAdxxpd qADxIpn p-n : pnnnpppnnpnLqADpLqADxIxII )0()0( 11/0/ kTqVkTqVpnnnppeIenLDpLDqAI: (diode equation) 1/ kTqVpnnnpprenLDpLDqAI V=Vr Vr kT/q , . 0 InLDpLDqAIpnnnpp . kTqVikTFFienenpnpn/2/)(2 p-n p-n.

7 P n p n . biased p-n . , , Fn Ec Fn Ev . p-n : (a) ( ). (b) . p+ n (a) (b) - V + biased p-n p-n . , . (breakdown diode) . , . ( ) ( ) ( ) ( ) ( ) dVdQC p-n (1) (2).

8 , . C=|Q/V| Q . p-n - (Ohmic) . (schottky contact) vs. (ohmic contact) - I-V .. p-n . p-n (masking) . I-V . , .. (image force) . - , (Schottky barrier diode) . n (a) n (b) (Schottky barrier) p (a) (b) n - (a) - ( ) (b).

9 - m . (c) - . (schottky contact) .. p-n .. p-n . kTqBeI/0 I-V - .. - .. (ohmic contact) - : (a) n m< s : . (b) : . (c) p m> s (d) : p . (a) (b) (c) (d) , . : ; , , (hetero-junction) p n (a) (b) n+-AlGaAs GaAs.

10 2 HEMT GaAs 2 . GaAs n+-AlGaAs GaAs ; (E1 E2) . - (Transistor) ? - (operation principle) - (space charge density) - MOS C-V - Real MOS cap. ( ) - (threshold voltage) - MOS - (C-V) interface trap - MOSFET & & - (short channel effects) (hot carrier) & e-h pairs , Punth-through, DIBL, (charge sharing), etc 3 3 . (on) (off).