Microtechnology/Semiconductors

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Semiconductors[edit]

Bandgap vs Lattice Const
Bandgap vs Lattice Const for Semiconductors - Wide range
Bandgap vs Lattice Const for 5.25-6.74 Å


Physical Semiconductor Properties Overview Table[edit]

Semiconductor Electronic Properties Overview Table
Element or Compound Name Crystal Structure Symmetry Group Lattice Constant (A) at 300 K Band Gap (ev) at 300 K Band Number of 1022 atoms cm-3 Density / g cm-3
IV
C Carbon (diamond) D ? 3.56683 5.47 I ? ?
C Graphite ? ? ? semimetal ? ? ?
C Nanotube ? ? ? prop. to 1/Ø[nm] ? ? ?
Ge Germanium D Oh7- Fd3m 5.64613 0.66 I 4.4 5.3234
Si Silicon D Oh7-Fd3m 5.43095 1.12 I 5 2.329
Sn Tin ? ? ? metal ? ? ?
Sn Grey Tin D ? 6.4892 0 D ? ?
IV-IV
SiC Silicon carbide W ? a = 3.086 and c= 15.117 2.996 I ? ?
III-V
AlAs Aluminum arsenide Z Td2-F43m[1] 5.6605 2.16 I ? 3.717[1]
AlP Aluminum phosphide Z Td2-F43m[1] 5.451 2.45 I[1] ? ?
AlSb Aluminum antimonide Z Td2-F43m[1] 6.1355 1.58 I ? 4.29[1]
BN Boron nitride Z ? 3.615 ~7.5 I ? ?
BP Boron phosphide Z ? 4.538 2 ? ? ?
GaAs Gallium arsenide Z Td2-F43m[1] 5.65325 1.42 D 4.42 5.32
GaN Gallium nitride W ? a = 3.189 and c = 5.185 3.36 ? ? ?
GaP Gallium phosphide Z Td2-F43m[1] 5.4512 2.26 I 4.94 4.14
GaSb Gallium antimonide Z Td2-F43m[1] 6.09593 0.72 D 3.53 5.61
InAs Indium arsenide Z Td2-F43m[1] 6.0584 0.36 D 3.59 5.68
InP Indium phosphide Z Td2-F43m[1] 5.8686 1.35 D 3.96 4.81
InSb Indium antimonide Z Td2-F43m[1] 6.4794 0.17 D 2.94 5.77
AlxGa1-xAs ? ? Td2-F43m 5.6533+0.0078x ? ? (4.42-0.17x) 5.32-1.56x
GaAsSbx ? ? Td2-F43m ? ? ? (4.42-0.89x) (5.32 + 0.29x)
II-VI
CdS Cadmium sulfide Z ? 5.832 2.42 D ? ?
CdS Cadmium sulfide W ? a = 4.16 and c = 6.756 2.42 D ? ?
CdSe Cadmium selenide Z ? 6.05 1.7 D ? ?
CdTe Cadmium telluride Z ? 6.482 1.56 D ? ?
ZnO Zinc oxide R ? 4.58 3.35 D ? ?
ZnS Zinc sulfide Z ? 5.42 3.68 D ? ?
ZnS Zinc sulfide W ? a = 3.82 and c = 6.26 3.68 D ? ?
ZnSe Zinc selenide Z ? 5.668 2.71 D ? ?
ZnTe Zinc telluride Z ? 6.103 2.393 D ? ?
IV-VI
PbS Lead sulfide R ? 5.9362 0.41 I ? ?
PbSe Lead selenide R ? 6.126 0.27 I ? ?
PbTe Lead telluride R ? 6.462 0.31 D ? ?
  • D = Diamond
  • W = Wurzite
  • Z = Zincblende
  • R = Rock Salt
  • I = Indirect
  • D = Direct
  • At ~ 2K

Some data from [2]

Electronic Semiconductor Properties Overview Table[edit]

Semiconductor Electronic Properties Overview Table
Element or Compound Name Debye temperature /K Dielectric constant (static) Dielectric constant high frequency (static) Electron affinity / eV Optical phonon energy / eV Effective electron mass me/mo Effective electron mass ml/mo Effective hole masses mh/mo Effective hole masses mlp/mo Effective hole masses ml Effective electron mass mt/mo Conductivity effective mass mcc Density-of-states electron mass mcd Auger recombination coefficient Cn Auger recombination coefficient Cp de Broglie electron wavelength Auger recombination coefficient
IV
C Carbon (diamond) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
C Graphite ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
C Nanotube ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Ge Germanium 374 16.2 ? 4 0.037 0.08 1.6 0.33 0.043 ? ? ? ? 10-30 cm6/s ? ? ?
Si Silicon 640 11.7 ? 4.05 0.063 0.19 0.98 0.49 0.16 ? ? ? ? 1.1·10-30 cm6 s-1 3·10-31cm6 s-1 ? ?
Sn Tin ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Sn Grey Tin ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
IV-IV
SiC Silicon carbide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
III-V
AlAs Aluminum arsenide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
AlP Aluminum phosphide ? 9.8[3] 7.5[4] ? ? ? 3.67[5] 0.513[6] 0.211[6] ? 0.212[5] ? ? ? ? ? ?
AlSb Aluminum antimonide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
BN Boron nitride ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
BP Boron phosphide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
GaAs Gallium arsenide 360 12.9 10.89 4.07 0.035 0.063 ? 0.51 0.082 ? ? ? ? ? ? 240 ?
GaN Gallium nitride ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
GaP Gallium phosphide 445 11.1 9.11 3.8 0.051 ? 1.12 0.79 0.14 ? 0.22 ? ? ? ? ? 10-30 cm6/s
GaSb Gallium antimonide 266 15.7 14.4 4.06 0.0297 0.041 ? 0.4 0.05 ? ? ? ? ? ? ? ?
InAs Indium arsenide 280 15.15 12.3 4.9 0.03 0.023 ? 0.41 0.026 ? ? ? ? ? ? 400 ?
InP Indium phosphide 425 12.5 9.61 4.38 0.043 0.08 ? 0.6 0.089 ? ? ? ? ? ? ? ?
InSb Indium antimonide 160 16.8 15.7 4.59 0.025 0.014 ? 0.43 0.015 ? ? ? ? ? ? ? ?
AlxGa1-xAs ? 370 + 54x + 22x^2 12.90 - 2.84x 10.89 - 2.73x 4.07 - 1.1x (x<0.45) and 3.64 - 0.14x (x>0.45) 36.25 + 1.83x + 17.12x^2 - 5.11x^3 meV 0.063 + 0.083x (x<0.45) ? 0.51 + 0.25x 0.082 + 0.068x ? ? 0.26 (x>0.45) 0.85 - 0.14x (x>0.45) ? ? ? ?
GaAsSbx ? ? 12.90 + 2.8x 10.89 + 3.51x 4.07 ? 0.063 - 0.0495x + 0.0258x^2 ? 0.51 - 0.11x ? 0.082 - 0.032x ? ? ? ? ? ? ?
II-VI
CdS Cadmium sulfide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
CdSe Cadmium selenide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
CdTe Cadmium telluride ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
ZnO Zinc oxide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
ZnS Zinc sulfide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
ZnSe Zinc selenide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
ZnTe Zinc telluride ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
IV-VI
PbS Lead sulfide ? ? ? ? ? 3.5[7] ? ? ? ? ? ? ? ? ? ? ?
PbSe Lead selenide ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
PbTe Lead telluride ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
  • D = Diamond
  • W = Wurzite
  • Z = Zincblende
  • R = Rock Salt
  • I = Indirect
  • D = Direct
  • At ~ 2K

Some data from [8]

Silicon[edit]

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 [9] [10].

Youngs modulus for polysilicon has values within that of crystalline silicon [11], which indicates that it is not affected by the grain boundaries, but is highly dependent on crystal orientation as well as the intrinsic stress [12].

Bulk shear modulus (which governs torsional motion) varies minimally on silicon (111), with respect to crystallographic directions, as compared to silicon (100) and (110)[13].

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 [14]

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[edit]

  • Extensive properties listing on [1] with "Resistivity & Mobility Calculator for Silicon Substrates"
Silicon Crystal Direction and Dopant Material Properties Overview Table - with gold for comparison to a metal
Orientation References Dopant Young's Modulus[GPa] Poisson's ratio Shear modulus [GPa] Thermal expansion [10-6] El. Resistivity [nΩ·m] Therm. Cond.[W·m−1·K−1] Piezores gauge factor Notes
Si 100 [13] ? 130.2-187.5 0.064-0.361 50.92-79.4 Therm exp El cond Therm cond PZgauge
Silicon 110 [13]

[15]

? 130.2-187.5 0.064-0.361 50.92-79.4 2.5-4.5 El cond Therm cond -52.7 to 121.3
Silicon 111 [13]

[15]

? 168.9 0.262 (parallel to the 111 plane)

0.182 (perpendicular to the 111 plane)

66.9 GPa (parallel to the 111 plane)

47.8 GPa (perpendicular to the 111 plane)

2.5-4.5 El cond Therm cond -14.1 to 175.8
Polysilicon [16]

[15]

? 130-169 Around 0.066-0.22 52-80 2.9 El cond Therm cond -10 to 30
Gold [17] none 78 0.44 27 14.2 22.14 318 4.48

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[edit]

IV Semiconductors[edit]

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[edit]

III-V Semiconductor Mechanical Properties
III-V Bulk Modulus GPa Youngs Mod. GPa Shear Modulus GPa Density g/cm³ Ref
GaAs 75.3 Yo[100]= 85.9 C'= 32.85 5.317 [2]
GaN 210 (W) 204 (Z) 181 67 6.15 [3]
GaP 88 Yo[100]= 103 C' = 39.2 4.138 [4]
InAs 58 Yo[100]= 51.4 C'= 19.0 5.68 [5]
InP 71 Yo[100]= 61.1 C'= 22.5 4.81 [6]

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[edit]

References[edit]

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

  1. a b c d e f g h i j k l http://www.semiconductors.co.uk/propiiiv5653.htm
  2. http://www.ioffe.ru/SVA/NSM/Semicond/index.html
  3. http://www.semiconductors.co.uk/propiiiv5653.htm
  4. S. Z. Beer, J. F. Jackovitz, D.W. Feldman and J.H. Parker Jr., "Raman and infrared active modes of aluminium phosphide", Physics Letters A Volume 26, Issue 7, Pages 331-332 (1968); doi:10.1016/0375-9601(68)90680-4
  5. a b I. Vurgaftman, J. R. Meyer, and L. R. Ram-Mohan, "Band parameters for III–V compound semiconductors and their alloys", J. Appl. Phys. 89, 5815 (2001); doi:10.1063/1.1368156
  6. a b Ming-Zhu Huang, and W.Y. Chinga, "A minimal basis semi-ab initio approach to the band structures of semiconductors", J. Phys. Chem. Solids 46 (1985) 977, DOI:10.1016/0022-3697(85)90101-5
  7. Artamonov, O. M.; Dmitrieva, O. G.; Samarin, S. N.; Yakovlev, I. I., Investigation of unoccupied electron states and determination of the electron affinity of PbS (100) by inverse photoemission spectroscopy, Semiconductors, Volume 27, Issue 10, October 1993, pp.955-957
  8. http://www.ioffe.ru/SVA/NSM/Semicond/index.html
  9. J. J. Wortman and R. A. Evans, “Young’s modulus, shear modulus, and Poissons ratio in silicon and germanium”, J. Appl. Phys., Vol. 36, 153-156 (1965).
  10. W. A. Brantley, “Calculated eleastic constants for stress problems associated with semiconductor devices”, J. Appl. Phys., vol. 44, 534-535 (1973).
  11. D. Maier-Schneider, J. Mansour, E. Oberheimer, D. Schneider, „Variation in Young’s Modulus and intrinsic stress of LPCVD-polysilicon due tohigh temperature annealing“, J. Micromech. Microeng. 3, 121-124 (1995).
  12. P. J. French, “Polysilicon: a versatile material for microsystems”, Sensors and Actuators A 99 (2002), 3-12
  13. a b c d J. Kim, D. Cho and R. S. Muller, “Why is (111) silicon a better mechanical material for MEMS?”, TRANSDUCERS '01. EUROSENSORS XV, vol.1, 662-665 (2001).
  14. W. N. Sharpe, K. M. Jackson, K. J. Hemker, and Z. Xie, “Effect of Specimen Size in Young’s Modulus and Fracture Strength of Polysilicon”, J. Microeletromechanical Systems, vol. 10, no. 2, 317-326 (2001).
  15. a b c V. M. Glazov and A. S. Pshinkin, ”The Thermophysical Properties (Heat Capacity and Thermal Expansion) of Single Crystal Silicon”, Springer New York, 2001. ISBN 0018-151X.
  16. C. S. Pan and W. Hsu, “An electro-thermally and laterally driven polysilicon microactuator”, J. Micromech. Microeng., vol 7, 7-13 (1997)
  17. Wikipedia: gold