SEMICONDUCTOR DEVICE PHYSICS AND DESIGN
5.2. METAL INTERCONNECTS 217 Element Work function, φm(volt) Ag, silver 4.26 Al, aluminum 4.28 Au, gold 5.1 Cr, chromium 4.5 Mo, ...
218 CHAPTER 5. SEMICONDUCTOR JUNCTIONS R = C ross-sectional area, A Lρ A R esistivity = ρ L W D L S heet resi stance = R W R =R ...
5.3. METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER 219 5.3 METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER The metal-semiconduct ...
220 CHAPTER 5. SEMICONDUCTOR JUNCTIONS SCHOTTKY METAL n Si p Si n GaAs Aluminum, Al 0.7 0.8 Titanium, Ti 0.5 0.61 Tungsten, W 0. ...
5.3. METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER 221 n-type or p-type semiconductor Metal ≈ ≈ φm > φs n-type Ec EFs n-semi ...
222 CHAPTER 5. SEMICONDUCTOR JUNCTIONS ≈ ≈ p-type Semiconductor Metal Evac p-semiconductor Metal (a) (b) eφs Ecs EFs Evs EFm Ec ...
5.3. METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER 223 EFm eφb= Eg – eφο EFs Ec Ev eφο Defect levels in the bandgap Figure 5.4: ...
224 CHAPTER 5. SEMICONDUCTOR JUNCTIONS EFm eVbi eφB x z y n n(E-EC) EC EFs Figure 5.5: Schottky Barrier in equilibrium Also show ...
5.3. METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER 225 The current density contributed by these electrons is Jz=−evz dN L^3 (5. ...
226 CHAPTER 5. SEMICONDUCTOR JUNCTIONS where A∗= 4 πem∗k^2 B 2 π^3 = 120Acm−^2 K−^2 × m∗ m 0 (5.3.21) is the Richardson constan ...
5.3. METAL SEMICONDUCTOR JUNCTION: SCHOTTKY BARRIER 227 saturation current(pn=2. 2 × 104 cm−^3 )(note that the saturation curren ...
228 CHAPTER 5. SEMICONDUCTOR JUNCTIONS p-n DIODE SCHOTTK Y DIODE R everse current is very low Forward current due to minority ca ...
5.4. METAL SEMICONDUCTOR JUNCTIONS FOR OHMIC CONTACTS 229 ––– – –– OHMIC CONTACT Electrons tunnel through narrow depletion r ...
230 CHAPTER 5. SEMICONDUCTOR JUNCTIONS barrier,theelectronscantunnelthroughthebarrierwithease, as shown in figure 5.7. The quali ...
5.5. INSULATOR-SEMICONDUCTOR JUNCTIONS 231 Insulator Semiconductor Interface defects Interface roughness Substrate { Figure 5.8: ...
232 CHAPTER 5. SEMICONDUCTOR JUNCTIONS 5.6 SEMICONDUCTOR HETEROJUNCTIONS ................. A growing number of modern devices ar ...
5.6. SEMICONDUCTOR HETEROJUNCTIONS 233 Ec eVd1 -Wn 0 Wp eVd2 Ev EF ΔEc ΔEv eΧ 1 eΧ 2 Eg1 Eg2 Ec1 EF1 Ev1 Evac Ec2 EF2 Ev2 (a) (b ...
234 CHAPTER 5. SEMICONDUCTOR JUNCTIONS -Wn 0 Wp 1,m 2,m + + + + + + + + + + + + + + + + + + + + + + + + (b) (a) E E E Figure 5.1 ...
5.6. SEMICONDUCTOR HETEROJUNCTIONS 235 W(Vbi)= [ 2 1 2 Vbi e ( [Na+Nd]^2 NaNd[Na 2 +Nd 1 ] )] 1 / 2 (5.6.9) E 1 ,m= eNdWn ...
236 CHAPTER 5. SEMICONDUCTOR JUNCTIONS Ec eΦBe -Wn 0 Wp eVd2 Ev EFp ΔEc ΔEv eVF eΦBh EFn Ec eΦBe -Wn 0 Wp eVd2 Ev eVF EFp eΦBh E ...
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