Drawing No. EH–MT–023 // Engineering Materials
Silicon Properties
Reviewed August 2026
Single-crystal silicon is the foundational semiconductor and also an important structural material in MEMS. Its stiffness is strongly crystallographic-direction dependent.
Representative properties
The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.
What changes these properties?
Engineering variability
- Elastic modulus varies with crystal orientation; [110] and [111] are stiffer than [100].
- Fracture strength is governed by surface flaws, etching, wafer thickness and fabrication process.
- Thermal conductivity depends on purity, defect density and temperature.
- Doping usually has modest effect on room-temperature thermal conductivity until carrier/impurity concentrations become high.
Selection note
Used for integrated circuits, MEMS, optical components and precision structures where crystalline anisotropy and brittle fracture must be considered.
Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.
How to interpret this material
Stiffness
Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.
Strength / failure
Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.
Thermal response
Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.
Technical sources
The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.