sábado, 13 de febrero de 2010

Materials Used in Semiconductor Manufacturing

Basic Elements Used Basic Elements Used

       
Silicon , symbol Si, is the most commonly used basic building block of integrated circuits.  Silicon is a semiconductor, which means that its electrical behavior is between that of a conductor and an insulator at room temperature.  With the proper addition of dopant elements, pn junctions can be formed on silicon.  Useful electronic components and integrated circuits can be built from pn junctions. Silicon, symbol Si, is the most commonly used basic building block of integrated circuits. Silicon is a semiconductor, which means that its electrical behavior is between that of a conductor and an insulator at room temperature. With the proper addition of dopant elements, pn junctions can be formed on silicon. Useful integrated circuits and electronic components can be built from pn junctions. Silicon is obtained by heating silicon dioxide (SiO2), or silica, with a reducing agent in a furnace.   Silicon dioxide is the main component of ordinary sand. Obtained by heating Silicon is silicon dioxide (SiO2), or silica, with a Reducing agent in a furnace. Silicon dioxide is the main component of ordinary sand.
   
Aside from being used as semiconductor substrate, silicon is also widely used as dielectric in integrated circuits, usually in the form of silicon dioxide.  Dielectric layers are used to isolate conductive lines and the individual components in the circuit from each other. Polycrystalline silicon, or polysilicon, is also used for making resistors or conductors in integrated circuits. Aside from being used as semiconductor substrate, silicon is also widely used as dielectric in integrated circuits, usually in the form of silicon dioxide. Dielectric layers are used to isolate conductive lines and the individual components in the circuit from each other. Polycrystalline silicon, or polysilicon, is also used for making resistors or conductors in integrated circuits. The top glassivation used to mechanically and electrically protect the die is also usually composed of silicon in the form of silicon nitride. The top glassivation used to mechanically and electrically protect the die is also usually composed of silicon in the form of silicon nitride. Silicon is also widely used in semiconductor packaging, being the main ingredient of plastic encapsulants for integrated circuits.  Silicon is also used in die overcoats. Silicon is also widely used in semiconductor packaging, being the main ingredient of plastic encapsulants for integrated circuits. Silicon is also used in die overcoats.

Table 1. Silicon's Basic Properties Silicon's Basic Properties
Property Property
Value Value
Property Property
Value Value
Atomic Number Atomic Number
14 14
Specific Gravity Specific Gravity
2.33 2.33
Atomic Group Atomic Group
14 or IVA 14 or VAT
Hardness Hardness
7 for crystalline silicon 7 for crystalline silicon
Atomic Weight Atomic Weight
28.086 28,086
Band Gap/Energy Gap Gap Band / Energy Gap
1.11 eV 1.11 eV
Melting Point Melting Point
1410 deg C 1410 deg C
Thermal Conductivity Thermal Conductivity
1.57 W/cm deg C 1.57 W / cm deg C
Boiling Temp Boiling Temp
2355 deg C 2355 deg C
Coeff. Coeff. of Thermal Expansion of Thermal Expansion
2.63e-6/deg C 2.63e-6/deg C

       
Aluminum , symbol Al, is a lightweight metal with silvery appearance.  It is the most abundant metallic element on earth. Aluminum is used in many aspects of semiconductor manufacturing.  On the integrated circuit, Al metal lines are commonly used as the main conductor between components, mainly because of its low resistivity (2.7 m ohm-cm). As a thin film, it also has good adherence to silicon dioxide. Aluminum, symbol Al, is a lightweight metal with silvery appearance. It is the most abundant metallic element on earth. Aluminum is used in many aspects of semiconductor manufacturing. On the integrated circuit, the metal lines are commonly used as the main driver between components , mainly Because of its low resistivity (2.7 m ohm-cm). As a thin film, it also has good adherence to silicon dioxide. Aluminum is also the metallization used for the bonding and probing pads on the die. Aluminum is also the Metallization used for the bonding and probing pads on the die. When used for IC metallization, Al is usually very lightly doped with other elements such as Si and/or Cu to improve its characteristics and reliability. When used for IC Metallization, Al is usually very lightly doped with other elements such as Si and / or Cu to Improve Its characteristics and reliability. In semiconductor assembly, ceramic packages are composed mainly of alumina. Aluminum is also used for wirebonding integrated circuits in ceramic packages. In semiconductor assembly, ceramic packages are composed mainly of alumina. Aluminum is also used for wirebonding integrated circuits in ceramic packages.
       
Table 2. Table 2. Aluminum's Basic Properties Aluminum's Basic Properties

Property Property
Value Value
Property Property
Value Value
Atomic Number Atomic Number
13 13
Melting Point Melting Point
660 deg C 660 deg C
Atomic Group Atomic Group
13 or IIIA 13 or IIIA
Boiling Temp Boiling Temp
2467 deg C 2467 deg C
Atomic Weight Atomic Weight
26.9815 26.9815
Specific Gravity Specific Gravity
2.7 2.7
Density Density
2.7 g/cm 3 2.7 g / cm 3
Resistivity Resistivity
2.7 m ohm-cm 2.7 m ohm-cm

       
Gold , symbol Au, is a soft metallic element that is bright yellowish in color. A good conductor of heat and electricity, it is also the most malleable and ductile of all metals. Gold is used in many aspects of semiconductor manufacturing, particularly in the assembly or packaging processes.  Its most widespread use is in wirebonding.  Because of gold's excellent conductivity and ductility, it is extensively used in making wires for the connection of the integrated circuit to the leads of the package.  Aside from manufacturability, the ductility of gold wires offers one more advantage when used in plastic-encapsulated devices, ie,  it makes the wires resistant to wire breaking during the encapsulation process. Gold, symbol Au, is a soft metallic element that is bright yellowish in color. A good conductor of heat and electricity, it is also the most Malleable and Ductile of all metals. Gold is used in many aspects of semiconductor manufacturing, Particularly in the assembly or packaging processes. Its most widespread use is in wirebonding. Because of gold's excellent conductivity and ductility, it is extensively used in making wires for the connection of the integrated circuit to the leads of the package. Aside from manufacturability, the ductility of gold wires offers one more advantage when used in plastic-encapsulated devices, ie, it makes the wires resistant to wire breaking during the encapsulation process. Gold is also used as die attach material for the eutectic die attach process, which is commonly used in old hermetic assembly processes.   Gold is also used to cover the die cavity and bonding posts of ceramic packages to protect these from chemical degradation. Gold is also used as die attach material for the Eutectic die attach process, Which is commonly used in old hermetic assembly processes. Gold is also used to cover the die cavity and bonding posts of ceramic packages to protect these from chemical degradation.
        
Table 3. Table 3. Gold's Basic Properties Gold's Basic Properties
Property Property
Value Value
Property Property
Value Value
Atomic Number Atomic Number
79 79
Melting Point Melting Point
1064 deg C 1064 deg C
Atomic Group Atomic Group
Transition Elements Transition Elements
Boiling Temp Boiling Temp
2808 deg C 2808 deg C
Atomic Weight Atomic Weight
196.97 196.97
Specific Gravity Specific Gravity
19.3 19.3

      
Silver , symbol Ag, is a shiny metallic element used for ornamental and coinage purposes since the ancient times. Silver, symbol Ag, is a shiny metallic element used for ornamental and coinage purposes since the ancient times.  It is next only to gold in terms of malleability and ductility, and is also a good conductor of heat and electricity.  In fact, silver is the best conductor of electricity, better even than copper and gold. Silver, like gold,  is used in many facets of semiconductor manufacturing, again more particularly in the assembly or packaging processes.  Most epoxy die attach materials contain silver fillers for increased thermal and electrical conductivity.  Silver is also used to cover the surfaces of the die pad and bonding fingers of the leadframes of plastic packages to prevent chemical degradation of these areas, which may lead to die attach and bonding problems. It is next only to gold in terms of malleability and ductility, and is also a good conductor of heat and electricity. In fact, silver is the best conductor of electricity, even better than copper and gold. Silver, like gold, is used in many facets of semiconductor manufacturing, again more particularly in the assembly or packaging processes. Most epoxy die attach materials contain silver fillers for increased thermal and electrical conductivity. Silver is also used to cover the surfaces of the die pad and bonding fingers of the leadframes of plastic packages to Prevent chemical degradation of these areas, Which may lead to die attach and bonding problems.
     
Table 4. Table 4. Silver's Basic Properties Silver's Basic Properties
Property Property
Value Value
Property Property
Value Value
Atomic Number Atomic Number
47 47
Melting Point Melting Point
962 deg C 962 deg C
Atomic Group Atomic Group
Transition Elements Transition Elements
Boiling Temp Boiling Temp
2212 deg C 2212 deg C
Atomic Weight Atomic Weight
107.868 107,868
Specific Gravity Specific Gravity
10.5 10.5

      
Copper , symbol Cu, is one of the most widely used metals in the history of mankind, mainly because of its  many desirable properties.  It is the second best conductor of electricity, next only to silver but better even than gold.  It also is very malleable and ductile, and is also a good conductor of heat. Copper is also widely used in semiconductor assembly.  For instance, most leadframes for plastic packages are composed of copper.   The leadframe is the skeletal support of a plastic package.  Copper, being an excellent conductor, would've been a very good candidate for use in metal lines in an  integrated circuit, but difficulties in the manufacturing of  IC's using copper for metallization resulted in Al being the metal of choice for this purpose.   Recent technological advancements though have already allowed the use of copper as metal lines in semiconductor devices. Copper, symbol Cu, is one of the most widely used metals in the history of mankind, mainly Because of its many desirable properties. It is the second best conductor of electricity, next only to silver but better even than gold. It also is very Malleable and ductile, and is also a good conductor of heat. Copper is also widely used in semiconductor assembly. For instance, most leadframes for plastic packages are composed of copper. The leadframe is the skeletal support of a plastic package. Copper, being an excellent driver, would've been a very good candidate for use in metal lines in an integrated circuit, but difficulties in the manufacturing of IC's using copper for Metallization search resulted in the being the metal of choice for this purpose. Recent technological advancements have already though allowed the use of copper as metal lines in semiconductor devices.
     
Table 5. Table 5. Copper's Basic Properties Copper's Basic Properties
Property Property
Value Value
Property Property
Value Value
Atomic Number Atomic Number
29 29
Melting Point Melting Point
1083 deg C 1083 deg C
Atomic Group Atomic Group
Transition Elements Transition Elements
Boiling Temp Boiling Temp
2567 deg C 2567 deg C
Atomic Weight Atomic Weight
63.546 63,546
Specific Gravity Specific Gravity
8.9 8.9

     
Hernandez Caballero Indiana M. CI: 15.242.745
Asignatura: EES
Fuente:http://translate.google.co.ve/translate?hl=es&sl=es&tl=en&u=http%3A%2F%2Fwww.siliconfareast.com%2Fsemicon_matls.htm


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