TEORI DASAR HUBUNGAN SEMIKONDUKTOR Hamzah Afandi Antonius Irianto
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<400 K) – 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/cm 3 (at 300 K)!
REVIEW: The Physics of Electronics Carrier’s Concentration in extrinsic Semiconductor Mass-Action Law pn = ni 2 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(x 0) p(x 1) x 0 x 1 x Dp = Diffusion Constant of Carrier
Review: Currents in semiconductor • Total Current: Jp Concentration p(x 0) p(x 1) x 0 x 1 x
Review: Graded semiconductor Jp = 0; in open circuited steady state condition V 21 p 2 Concentration p(x 1) p(x 2) x 1 x 2 x
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 Semiconductors Holes p type Electrons n type
Open Circuited Junction Formation Junction p type n type Depletion Region Space Charged Region
Open Circuited Junction Formation Charge Density ( V) -Wp Wn p type n type Depletion Region Space Charged Region
Open Circuited Junction Formation Wn -Wp p type Field Intensity ( ) Depletion Region Space Charged Region n type
Open Circuited Junction Formation -Wp Wn V=0 p type Electrostatic Potential (V)n Depletion Region Space Charged Region type V 0
Open Circuited Junction Formation Potential Barrier of electrons(V) -Wp Wn V=0 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 IS ( A Scale) Breakdown VD Cut-in Offest Turn-on
Diode Circuit Analysis: Load-Line Concept R VAA + ID _ + _ VD ID VAA /R Solve for: VAA = 3 V R = 2 K IDQ Q VD VDQ VAA
CALCULATION EXAMPLES Given in class
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