silicon. occurs as silica (sio 2 ) & other silicates. hard & brittle
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Silicon
Silicon
Occurs as silica (SiO2) & other silicates.Hard & Brittle.
Forms Of Silica
Agate Opal
Pure Silicon
Pure Silicon
Intrinsic Silicon.Covalent Bond.Insulator.Resistivity 2.5 x 105 ohms-cm
Pure Silicon
Pure Silicon Bonding
Why Silicon
Why Silicon
Abundance of SiliconHigher Melting Temperature for Wider
Processing Range.Wider Temperature range of operationNatural growth of SiO2
Why Silicon
• SiO2 growth is needed for high performance MOS.
Doped Silicon
Doping
Adding Certain Elements to Enhance the Conductivity of Semiconductor.
Becomes Extrinsic.Resistivity drops to 0.2 ohms-cm.
Doping of Silicon
Dopant Material
Dopant Material
n-Type Silicon
n-Type Silicon
Pentavalent Dopant Used.More Electrons than Valance Band Holes.Need Little Energy for Excess Electron to Go to
Conduction Band.Majority Carrier Electron & Minority Carrier
Hole.
n-Type Silicon
p-Type Silicon
p-Type Silicon
Trivalent Dopant usedMore Valance Band Holes than Conduction
Band Electrons.Majority Carrier Hole & Minority Carrier
Electron.
p-Type Silicon
p & n Type Silicon
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