Microtechnology/Semiconductors

=Semiconductors=

Physical Semiconductor Properties Overview Table

 * D = Diamond
 * W = Wurzite
 * Z = Zincblende
 * R = Rock Salt
 * I = Indirect
 * D = Direct
 * At ~ 2K

Some data from

Electronic Semiconductor Properties Overview Table

 * D = Diamond
 * W = Wurzite
 * Z = Zincblende
 * R = Rock Salt
 * I = Indirect
 * D = Direct
 * At ~ 2K

Some data from

=Silicon=

The traditional material for microfabrication is silicon and a wealth of processes have been developed to work with silicon wafers.

There are several different silicon crystal orientations as well as polycrystalline silicon (often called polysilicon) to choose between, and these orientations all have their own material parameters.

The Young’s modulus, Poisson’s ratio, and shear modulus are transversely and vertically isotropic for Si111 whereas these vary significantly for Si100 and Si110 .

Youngs modulus for polysilicon has values within that of crystalline silicon , which indicates that it is not affected by the grain boundaries, but is highly dependent on crystal orientation as well as the intrinsic stress.

Bulk shear modulus (which governs torsional motion) varies minimally on silicon (111), with respect to crystallographic directions, as compared to silicon (100) and (110).

It should be kept in mind that the values of Young’s modulus for microstructures are very much dependent on the size of the structure

Silicon is a nonlinear material, where the material parameters such as thermal coefficient of expansion, conductivity, and piezoresistivity  all depend on the temperature. Care must be taken when modelling the behaviour devices with a wide temperature variation.

Silicon Material Properties Overview Table

 * Extensive properties listing on with "Resistivity & Mobility Calculator for Silicon Substrates"

This table indicates that Si 111 is an attractive material compared to other Si crystal orientations when only considering the mechanical properties, because it is providing a rigid structure by the high Young’s modulus, low Poisson’s ratio, high shear modulus and also the simplest because it is transversely and vertically isotropic.

=Polycrystalline Silicon=

=IV Semiconductors= Of the IV group elements C,Si,Ge,Sn,Pb; Si and Ge are considered semiconductors although graphite,a allotropic form of carbon is conducting but its conductivity is too high than the standard semiconductors.So,it is like the metal.

=III-V Semiconductors=

Units
 * 1 N = 10^5 dyn
 * 1 GPa= 10^9 N /m2= 10^9+5dyn/m2= 10^9+5-4 dyn cm-2=10^10 dyn/cm2
 * 1 g/cm3 = 1 kg/L = 1000 kg/m3

=II-VI Semiconductors=

=References=

See also notes on editing this book about how to add references Microtechnology/About.