Microtechnology/Semiconductors

Semiconductors + Bandgap vs Lattice Constthumb|400px|Bandgap vs Lattice Const for Semiconductors - Wide rangethumb|400px|Bandgap vs Lattice Const for 5.25-6.74 Å Physical Semiconductor Properties Overview Table +Semiconductor Electronic Properties Overview TableElement or CompoundNameCrystal StructureSymmetry GroupLattice Constant (A) at 300 KBand Gap (ev) at 300 KBandNumber of 1022 atoms cm-3Density / g cm-3IVCCarbon (diamond)D?3.566835.47I??CGraphite???semimetal???CNanotube???prop. to 1/Ø[nm]???GeGermaniumDOh7- Fd3m5.646130.66I4.45.3234SiSiliconDOh7-Fd3m5.430951.12I52.329SnTin???metal???SnGrey TinD?6.48920D??IV-IVSiCSilicon carbideW?a = 3.086 and c= 15.1172.996I??III-VAlAsAluminum arsenideZTd2-F43mhttp://www.semiconductors.co.uk/propiiiv5653.htm5.66052.16I?3.717AlPAluminum phosphideZTd2-F43m5.4512.45I??AlSbAluminum antimonideZTd2-F43m6.13551.58I?4.29BNBoron nitrideZ?3.615~7.5I??BPBoron phosphideZ?4.5382???GaAsGallium arsenideZTd2-F43m5.653251.42D4.425.32GaNGallium nitrideW?a = 3.189 and c = 5.1853.36???GaPGallium phosphideZTd2-F43m5.45122.26I4.944.14GaSbGallium antimonideZTd2-F43m6.095930.72D3.535.61InAsIndium arsenideZTd2-F43m6.05840.36D3.595.68InPIndium phosphideZTd2-F43m5.86861.35D3.964.81InSbIndium antimonideZTd2-F43m6.47940.17D2.945.77AlxGa1-xAs??Td2-F43m5.6533+0.0078x??(4.42-0.17x)5.32-1.56x GaAsSbx??Td2-F43m???(4.42-0.89x)(5.32 + 0.29x)II-VICdSCadmium sulfideZ?5.8322.42D??CdSCadmium sulfideW?a = 4.16 and c = 6.7562.42D??CdSeCadmium selenideZ?6.051.7D??CdTeCadmium tellurideZ?6.4821.56D??ZnOZinc oxideR?4.583.35D??ZnSZinc sulfideZ?5.423.68D??ZnSZinc sulfideW?a = 3.82 and c = 6.263.68D??ZnSeZinc selenideZ?5.6682.71D??ZnTeZinc tellurideZ?6.1032.393D??IV-VIPbSLead sulfideR?5.93620.41I??PbSeLead selenideR?6.1260.27I??PbTeLead tellurideR?6.4620.31D?? D = Diamond W = Wurzite Z = Zincblende R = Rock Salt I = Indirect D = Direct At ~ 2K Some data from http://www.ioffe.ru/SVA/NSM/Semicond/index.html Electronic Semiconductor Properties Overview Table +Semiconductor Electronic Properties Overview TableElement or CompoundNameDebye temperature /KDielectric constant (static)Dielectric constant high frequency (static)Electron affinity / eVOptical phonon energy / eVEffective electron mass me/moEffective electron mass ml/moEffective hole masses mh/moEffective hole masses mlp/moEffective hole masses mlEffective electron mass mt/moConductivity effective mass mccDensity-of-states electron mass mcdAuger recombination coefficient CnAuger recombination coefficient Cpde Broglie electron wavelengthAuger recombination coefficientIVCCarbon (diamond)?????????????????CGraphite?????????????????CNanotube?????????????????GeGermanium37416.2?40.0370.081.60.330.043????10-30 cm6/s???SiSilicon64011.7?4.050.0630.190.980.490.16????1.1·10-30 cm6 s-13·10-31cm6 s-1??SnTin?????????????????SnGrey Tin?????????????????IV-IVSiCSilicon carbide?????????????????III-VAlAsAluminum arsenide?????????????????AlPAluminum phosphide?9.8http://www.semiconductors.co.uk/propiiiv5653.htm7.5S. 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???3.67I. 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:10.1063/1.13681560.513Ming-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)90101-50.211?0.212??????AlSbAluminum antimonide?????????????????BNBoron nitride?????????????????BPBoron phosphide?????????????????GaAsGallium arsenide36012.910.894.070.0350.063?0.510.082??????240?GaNGallium nitride?????????????????GaPGallium phosphide44511.19.113.80.051?1.120.790.14?0.22?????10-30 cm6/sGaSbGallium antimonide26615.714.44.060.02970.041?0.40.05????????InAsIndium arsenide28015.1512.34.90.030.023?0.410.026??????400?InPIndium phosphide42512.59.614.380.0430.08?0.60.089????????InSbIndium antimonide16016.815.74.590.0250.014?0.430.015????????AlxGa1-xAs?370 + 54x + 22x^212.90 - 2.84x10.89 - 2.73x4.07 - 1.1x (x<0.45) and 3.64 - 0.14x (x>0.45)36.25 + 1.83x + 17.12x^2 - 5.11x^3 meV0.063 + 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 + 2.8x10.89 + 3.51x4.07?0.063 - 0.0495x + 0.0258x^2 ?0.51 - 0.11x ?0.082 - 0.032x ???????II-VICdSCadmium sulfide?????????????????CdSeCadmium selenide?????????????????CdTeCadmium telluride?????????????????ZnOZinc oxide?????????????????ZnSZinc sulfide?????????????????ZnSeZinc selenide?????????????????ZnTeZinc telluride?????????????????IV-VIPbSLead sulfide?????3.5Artamonov, 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???????????PbSeLead selenide?????????????????PbTeLead telluride????????????????? D = Diamond W = Wurzite Z = Zincblende R = Rock Salt I = Indirect D = Direct At ~ 2K Some data from http://www.ioffe.ru/SVA/NSM/Semicond/index.html 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 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). W. A. Brantley, “Calculated eleastic constants for stress problems associated with semiconductor devices”, J. Appl. Phys., vol. 44, 534-535 (1973).. Youngs modulus for polysilicon has values within that of crystalline silicon 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)., which indicates that it is not affected by the grain boundaries, but is highly dependent on crystal orientation as well as the intrinsic stress P. J. French, “Polysilicon: a versatile material for microsystems”, Sensors and Actuators A 99 (2002), 3-12. Bulk shear modulus (which governs torsional motion) varies minimally on silicon (111), with respect to crystallographic directions, as compared to silicon (100) and (110) 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).. 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 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). 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" + Silicon Crystal Direction and Dopant Material Properties Overview Table - with gold for comparison to a metalOrientationReferencesDopantYoung's Modulus[GPa]Poisson's ratioShear modulus [GPa]Thermal expansion [10-6]El. Resistivity [nΩ·m]Therm. Cond.[W·m−1·K−1]Piezores gauge factorNotesSi 100?130.2-187.50.064-0.36150.92-79.4Therm expEl condTherm condPZgaugeSilicon 110V. 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.?130.2-187.50.064-0.36150.92-79.42.5-4.5El condTherm cond-52.7 to 121.3Silicon 111?168.90.262 (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)2.5-4.5El condTherm cond-14.1 to 175.8Polysilicon C. S. Pan and W. Hsu, “An electro-thermally and laterally driven polysilicon microactuator”, J. Micromech. Microeng., vol 7, 7-13 (1997)?130-169Around 0.066-0.2252-802.9El condTherm cond-10 to 30GoldWikipedia: goldnone780.442714.222.143184.48 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 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 + III-V Semiconductor Mechanical PropertiesIII-VBulk Modulus GPaYoungs Mod. GPaShear Modulus GPaDensity g/cm³RefGaAs75.3Yo[100]= 85.9C'= 32.855.317GaN210 (W) 204 (Z)181676.15GaP88Yo[100]= 103C' = 39.24.138InAs58Yo[100]= 51.4C'= 19.05.68InP71Yo[100]= 61.1C'= 22.54.81 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#How to Contribute.