TEORI DASAR HUBUNGAN SEMIKONDUKTOR Hamzah Afandi, Antonius Irianto dan Betty Savitri Source: Millman, Jacob, Grabel, Arvin, Microelectronics, Mc. Graw Hill Int. Ed., 1994. Robert Boylestad, Louis Nashelsky Sixth Edition; Prentice Hall,1997.

Review: Semiconductor Properties Variation Intrisic Concentration vs Temperature: Mobility vs Temperature: ; mn=2.5, mp=2.7 (100<T<400K) Mobility vs Electric Field intensity: ~ 107 cm/s 103 V/cm 104 V/cm

Review: Currents in semiconductor Drift Current: Drill: Calculate the conductivity of an extrinsic semiconductor with donor atom’s concentration of 1016 atom/cm3 (at 300K)!

Charge Density should maintain electric neutrality of crystal REVIEW: The Physics of Electronics Carrier’s Concentration in extrinsic Semiconductor Mass-Action Law pn = ni2 Charge Density should maintain electric neutrality of crystal For n-type semiconductor, NA = 0; thus: For p-type semiconductor, ND = 0; thus:

Review: Currents in semiconductor Jp Diffusion Current: Einstein Relationship between D and  Concentration p(x0) p(x1) x0 x1 x Dp = Diffusion Constant of Carrier

Review: Currents in semiconductor  Total Current: Jp Concentration p(x0) p(x1) x0 x1 x

Review: Graded semiconductor Concentration x x1 x2 p(x1) p(x2) V21 p1 p2 Jp = 0; in open circuited steady state condition

Hamzah Afandi, Antonius Irianto dan pn JUNCTION DIODE Hamzah Afandi, Antonius Irianto dan Betty Savitri Source: Millman, Jacob, Grabel, Arvin, Microelectronics, Mc. Graw Hill Int. Ed., 1994.

Open Circuited Junction neutral neutral Semiconductors Semiconductors Holes Electrons p type n type

Open Circuited Junction Junction Formation p type n type Depletion Region Space Charged Region

Open Circuited Junction Junction Formation Charge Density (V) Wn -Wp p type n type Depletion Region Space Charged Region

Open Circuited Junction Junction Formation Wn -Wp Field Intensity () p type n type Depletion Region Space Charged Region

Open Circuited Junction Junction Formation V0 Wn -Wp V = 0 Electrostatic Potential (V) p type n type Depletion Region Space Charged Region

Open Circuited Junction Junction Formation Potential Barrier of electrons(V) Wn -Wp V0 V = 0 p type n type Depletion Region Space Charged Region

Closed Circuited Junction Forward Biased pn Junction p type n type Depletion Region Space Charged Region

Closed Circuited Junction Forward Biased pn Junction p type n type Depletion Region Space Charged Region

Closed Circuited Junction Reverse Biased pn Junction p type n type Depletion Region Space Charged Region

Closed Circuited Junction Reverse Biased pn Junction p type n type Depletion Region Space Charged Region

Closed Circuited Junction Reverse Biased pn Junction p type n type Depletion Region Space Charged Region

VOLT-AMPERE CHARACTERISTIC  = 2 (Si)  = 1.5 (Ge) ID V -VZ VD IS (A Scale) Cut-in Offest Turn-on Breakdown

Diode Circuit Analysis: Load-Line Concept + _ VAA R VD ID ID VAA /R Solve for: VAA = 3 V R = 2 K IDQ Q VD VDQ VAA

CALCULATION EXAMPLES Given in class