ForMatter/Materials/other/Silicon (Electronic-Grade Single Crystal)
mat_silicon_electronic_grade

Silicon (Electronic-Grade Single Crystal)

single-crystal semiconductor element, diamond-cubic lattice, electronic-grade purity · Si, monocrystalline silicon, EG-Si, 9N silicon, semiconductor-grade silicon, single-crystal silicon, wafer silicon
highlast updated 2026-04-28

The substrate of every microprocessor, every memory chip, every digital camera image sensor, every MEMS accelerometer in a phone, every solar cell. A pure crystalline form of the same element that makes up most of sand and quartz, refined to a level of purity unmatched by any other industrial material — better than 99.9999999 percent (the 'nine nines' standard for electronic grade). Pulled out of a melt as a single-crystal cylinder (the boule), then sliced with a diamond wire saw into wafers a fraction of a millimeter thick, polished to a flatness that defies casual measurement, and patterned by photolithography with billions of transistors per square centimeter. The 300 mm (12 inch) wafer is the modern semiconductor-fab standard; 200 mm wafers persist for older nodes; 450 mm wafers were proposed but stalled. Less-pure 'solar-grade' silicon (six nines) makes photovoltaic cells. Polysilicon (small randomly-oriented crystals) is the precursor to either grade. Buy electronic-grade wafers from Shin-Etsu (Japan), SUMCO (Japan), GlobalWafers (Taiwan), or Siltronic (Germany); buy solar-grade ingots from Wacker, Hemlock, GCL, or Daqo.

Group 14 element, diamond-cubic crystal structure (lattice constant 5.431 Å), atomic number 14, atomic mass 28.09. Indirect bandgap 1.12 eV at 300 K — the property that lets silicon function as the transistor channel material. Density 2329 kg/m³ at 25 °C (single crystal). Melting point 1414 °C; the liquid is denser than the solid (the unusual property exploited in Czochralski boule-pulling: a seed crystal is dipped into the melt and slowly withdrawn while rotating, growing the boule as the melt level drops). Young's modulus 130–188 GPa (orientation-dependent — Si is mechanically anisotropic; ⟨100⟩ is softest, ⟨111⟩ is stiffest). Mohs hardness 7 (between feldspar and quartz). Thermal conductivity 149 W/m·K at 25 °C — much higher than glass; comparable to many metals. Coefficient of thermal expansion 2.6 × 10⁻⁶ /K (the property that makes silicon dimensionally stable enough to host integrated circuits). Refractive index 3.42 at 1550 nm IR (silicon is opaque in visible but transparent in near-IR — the basis of silicon photonics). Two production routes: (1) CZOCHRALSKI (CZ) — seed-and-pull from a quartz crucible melt, the canonical method for IC wafers; produces 200–450 mm boules with ~1 ppm oxygen contamination from the crucible, fine for most CMOS; (2) FLOAT ZONE (FZ) — RF-induction-melted zone slowly traversed up a vertical polysilicon rod, no crucible contact, ultralow oxygen, used for power-electronic and photonic-grade material. Wafers polished to better than λ/10 flatness (chemo-mechanical polish, CMP, with colloidal silica and dilute KOH); the resulting surface is the canonical reference for atomic-force-microscope calibration. Dopants: boron (p-type, group 13) at 10¹⁴–10²⁰ atoms/cm³; phosphorus / arsenic / antimony (n-type, group 15) at similar range. Etches anisotropically in KOH or TMAH, isotropically in HNA (HF/HNO3/acetic), making it the canonical MEMS structural material. The ASML EUV (extreme ultraviolet, 13.5 nm wavelength) photolithography systems pattern silicon wafers at the 3 nm node and below — the contemporary frontier of precision manufacturing.

mechanical

  • density_kg_m32329
  • youngs_modulus_gpa_100130
  • youngs_modulus_gpa_111188
  • tensile_strength_mpa7000
  • mohs_hardness7
source: Hull, *Properties of Crystalline Silicon* (INSPEC, 1999); Shin-Etsu wafer datasheet

thermal

  • melting_point_c1414
  • thermal_conductivity_w_mk149
  • coefficient_thermal_expansion_per_k2.6e-06
  • specific_heat_j_kg_k705
source: NIST silicon reference data; Shin-Etsu / SUMCO wafer datasheets

electrical

  • bandgap_ev_300k1.12
  • intrinsic_resistivity_ohm_cm230000
  • electron_mobility_cm2_vs1400
  • hole_mobility_cm2_vs450
source: Sze, *Physics of Semiconductor Devices* (Wiley, 2007); industry-standard physics constants

optical

  • refractive_index_1550nm3.42
  • transparent_band_um1.1-7
source: Palik, *Handbook of Optical Constants of Solids* (Academic Press, 1985)

Sustainability

  • embodied carbon kg co2e per kg1100
  • sourceEditorial estimate. Electronic-grade silicon is among the highest-embodied-carbon materials per kg in industrial use because the purification cascade (metallurgical-grade → polysilicon via Siemens / FBR process → CZ pulling → wafer slicing → CMP polishing) consumes vast amounts of energy and high-purity feedstock. Solar-grade silicon (six-nines, vs nine-nines for electronic) is roughly 10× lower per kg. The per-chip carbon load is small only because each wafer carries thousands of dies and each die hosts billions of transistors.
  • recyclabilitylow at the chip / wafer level — once doped and patterned, silicon is rarely recovered as silicon (it's too contaminated to re-melt to electronic grade). Off-spec polysilicon and pre-CZ scrap is closed-loop recycled within the supply chain. End-of-life chips are mostly landfilled or incinerated for the metal contacts.
  • biodegradableFalse
  • certificationsSEMI M1 (silicon wafer specifications), SEMI F47 (voltage-sag immunity for fabs)
  • localityprimary global production Shin-Etsu (Japan), SUMCO (Japan), GlobalWafers (Taiwan), Siltronic (Germany), SK Siltron (Korea); polysilicon feedstock from Wacker (Germany), Hemlock (US), GCL (China), Daqo (China). EUV photolithography systems exclusively from ASML (Netherlands). Designer-quantity wafers (test grade, 100 mm typical) via University Wafer, El-Cat, MTI Corp.
visual
polished single-crystal silicon is mirror-like with a subtle warm-gray cast; thicker pieces look near-black; in cross-section the cleaved {111} face shows the characteristic mirror-flat brittle-fracture surface that distinguishes a brittle covalent crystal from any metal
tactile
extraordinarily smooth — the polished wafer surface is the canonical reference for 'optically flat'; cool to the touch (high thermal mass per kg); brittle — wafers chip on edge contact and shatter on drop
weight perception
moderate — heavier than glass for the same volume but much lighter than metals
acoustic
a clear high tap when struck (high modulus, low damping); broken silicon makes the distinctive thin-glass tinkle, not a metal ring
Simon Winchester (living — quote)

It takes an enormous machine to allow for the making of something so infinitesimally tiny as a computer chip.

Winchester, *The Perfectionists: How Precision Engineers Created the Modern World* (HarperCollins, 2018), Chapter 9, 'Squeezing Beyond Boundaries,' caption to the ASML Twinscan NXE:3350B EUV photolithography machine — a $100 million system that 'would fill three jet cargo aircraft' and that pattern-prints transistors at the contemporary frontier of precision.
Tim Minshall (living — quote)

This is engineering at an unbelievable level of precision and complexity.

Minshall, *Your Life Is Manufactured: How We Make Things, Why It Matters and How We Can Do It Better* (Faber, 2025), Chapter 6 on the semiconductor industry, on Apple's M3 Max microprocessor (2024) — 92 billion transistors on a die roughly the size of a small fingernail. Tim Minshall is the inaugural Dr John C. Taylor Professor of Innovation at the University of Cambridge and Head of the Institute for Manufacturing.
Ed Conway (living — quote)

After oxygen, which attaches itself to pretty much everything else, silicon is comfortably the most common element in the earth's crust. Given this ubiquity, it's perhaps unsurprising we've found so many different things to do with it. We dig and quarry and blast more sand out of the earth than any other material. Yet the economic enigma of sand is that in certain guises it is very precious, so much so that the European Union deems its purest, most elemental forms a critical raw material.

Conway, *Material World: The Six Raw Materials That Shape Modern Civilization* (Knopf, 2023), Part One: Sand, Chapter 2 'Built upon Sand,' on the silica-purity paradox that defines the supply chain from common beach sand to electronic-grade single-crystal silicon. Conway frames silicon as 'the great enigma of the Material World' — abundant in mass but scarce in the high-purity guises that make modern computing possible. Ed Conway (b. 1979) is Economics Editor of Sky News; verified living 2026-04-28.

PBR starter values

finish · metallic — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere metallic finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   metallic
albedo                      #454850
metallic                    0.70
roughness                   0.05
ior                         1.45
transmission                0.00
clearcoat                   0.00
sheen                       0.00
anisotropic                 0.00
copy as JSON 
{
  "albedo": "#454850",
  "metallic": 0.7,
  "roughness": 0.05,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Silicon (Electronic-Grade Single Crystal) · finish: metallic
import bpy
mat = bpy.data.materials.new(name="mat_silicon_electronic_grade")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.0595, 0.0648, 0.0802, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.700
bsdf.inputs["Roughness"].default_value          = 0.050
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.000
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux) 
# KeyShot 11+ — lux Python API, Generic material
# Silicon (Electronic-Grade Single Crystal) · finish: metallic
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_silicon_electronic_grade", materialType="Generic")
mat.setProperty("diffuse",      (69, 72, 80))   # 8-bit sRGB
mat.setProperty("metallic",     0.700)
mat.setProperty("roughness",    0.050)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.000)
Substance pbrMetalRough 
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "Silicon (Electronic-Grade Single Crystal) \u00b7 finish: metallic",
  "baseColor": {
    "r": 0.0595,
    "g": 0.0648,
    "b": 0.0802
  },
  "metallic": 0.7,
  "roughness": 0.05,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness 
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_silicon_electronic_grade",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.0595,
          0.0648,
          0.0802,
          1.0
        ],
        "metallicFactor": 0.7,
        "roughnessFactor": 0.05
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Silicon (Electronic-Grade Single Crystal) · finish: metallic
def Material "mat_silicon_electronic_grade" {
    token outputs:surface.connect = </mat_silicon_electronic_grade/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.0595, 0.0648, 0.0802)
        float   inputs:metallic     = 0.700
        float   inputs:roughness    = 0.050
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material
ProcessCNC Milling · Laser Cutting
Used inMacBook Pro Chassis · Consumer-Electronics Enclosure
Substitutes
Silicon Carbide (SiC, Carborundum)
Fused Quartz (High-Purity Silica Glass)
Where to buyhttps://www.universitywafer.com/

Second life

repairabilityzero at the wafer level — committed once the chip is patterned.
recyclabilitymoderate — electronic-grade silicon recycling exists for failed wafers and end-of-life chips, but volumes small relative to production.
disposal pathspecialty electronics recycler; some scrap routes for off-spec wafer material.
typical longevity20 years (typical)
failure modes
  • electromigration in interconnects (the canonical chip-failure mode)
  • oxide breakdown under sustained voltage stress
  • thermal cycling fatigue at solder joints

Conway *Material World* Sand chapter; Shin-Etsu / SUMCO wafer datasheets; SEMI International standards.

Citations

  • url · https://en.wikipedia.org/wiki/Wafer_(electronics)
  • url · https://en.wikipedia.org/wiki/Czochralski_process
  • standard · SEMI M1 — Specifications for Polished Single Crystal Silicon Wafers
  • book · Hull, *Properties of Crystalline Silicon* (INSPEC, 1999) — the canonical materials-science reference for single-crystal silicon.
  • book · Sze, *Physics of Semiconductor Devices* (Wiley, 3rd ed. 2007) — the canonical device-physics reference.
  • book · Winchester, *The Perfectionists: How Precision Engineers Created the Modern World* (HarperCollins, 2018), Chapter 9 — ASML / Intel / Moore's law as the contemporary frontier of precision manufacturing.
  • book · Minshall, *Your Life Is Manufactured: How We Make Things, Why It Matters and How We Can Do It Better* (Faber, 2025), Chapter 6 — semiconductor manufacturing as the most complex sustained industrial system.
  • book · Conway, *Material World: The Six Raw Materials That Shape Modern Civilization* (Knopf, 2023), Part One: Sand — silicon as the most common element after oxygen, and the silica-purity supply chain from beach sand to electronic-grade wafer.

Further reading