Semiconductor materials
A modern semiconductor is built from many carefully engineered materials. Explore what each one is, where it is used, and why it matters — always in the context of making a chip.
Start here
New to materials? Follow the simplified journey a chip’s materials take, from wafer to package.
Explore by process
Prefer the process view? See the manufacturing steps and the equipment that works these materials.
Explore by material type
Already know your way around? Jump straight to a material family.
The materials journey
A chip is built up from many material families, roughly in this order. Layers repeat many times, and not every process uses exactly this sequence — but it is a useful way to see how the materials fit together.
After fabrication: the packaging materials
Once the wafer is finished, a second set of materials turns each die into a connected, protected package — attaching it, wiring it, moving its heat, encapsulating it, and routing it out. Exact sequences differ by package technology.
Materials by type
Each material family, in plain terms. Follow a link to learn the process that uses it or the equipment that works it; families marked Soon aren’t written yet.
Semiconductor materials
- What it is
- The base semiconducting material a device is built from — most often silicon, sometimes a compound such as gallium arsenide or silicon carbide.
- Where it fits
- The foundation of the whole device — everything else is added on top.
- Why it matters
- Its properties (how it conducts, its crystal quality, its purity) set the ceiling for device performance; this is the material that can be 'switched'.
Wafers & substrates
- What it is
- The polished single-crystal slice that devices are built on, grown from a large crystal (ingot) and cut into wafers.
- Where it fits
- The very start — the physical platform for every later step.
- Why it matters
- Flatness, purity, and crystal perfection set the floor for everything after; defects here propagate into every device.
Photoresists
- What it is
- Light-sensitive films that record the circuit pattern when exposed, so it can be developed and transferred into the wafer.
- Where it fits
- At the start of every patterned layer, in lithography.
- Why it matters
- The resist's sensitivity and resolution help set the smallest feature that can be printed; it is the recording medium for the pattern.
Dielectrics
- What it is
- Insulating materials — grown oxides and deposited dielectrics — that separate conductors and form gate insulators.
- Where it fits
- Throughout the stack: gate insulators, and insulation between wiring layers.
- Why it matters
- They stop current where it should not flow; the thinnest (gate) dielectrics must be controlled to within a few atoms, and their quality sets leakage and reliability.
Conductors
- What it is
- The metals that carry signals and power — the interconnect wiring, contacts, and barrier/liner layers.
- Where it fits
- The wiring stack that connects millions of devices, built up layer by layer.
- Why it matters
- Their resistance and reliability set how fast and how reliably signals move; interconnect increasingly limits chip performance.
Deposition materials
- What it is
- The source materials for thin films — sputter targets and gas-phase precursors used by PVD, CVD, and ALD.
- Where it fits
- Wherever a new film layer is added — many times across the flow.
- Why it matters
- Precursor and target purity and chemistry determine film quality, composition, and defectivity — and thus device behaviour.
Dopant materials
- What it is
- The dopant species introduced into silicon to change how regions conduct (for example boron, phosphorus, arsenic).
- Where it fits
- To form transistor source/drain regions, wells, and threshold adjustments.
- Why it matters
- Doping is what turns plain silicon into a device; the dopant, dose, and depth set transistor behaviour.
Etch chemistry
- What it is
- The liquid chemicals and reactive process gases that remove material selectively during etch.
- Where it fits
- After lithography, on nearly every patterned layer.
- Why it matters
- The chemistry sets selectivity and profile — how cleanly the pattern becomes real 3D structure without harming other layers.
CMP materials
- What it is
- The polishing slurries (chemistry plus fine abrasives) and pads used to planarize the wafer between layers.
- Where it fits
- Between build-up layers, especially across the interconnect stack.
- Why it matters
- Slurry and pad behaviour set removal rate, selectivity, and planarity — and are a real source of defects if not controlled.
Packaging materials
- What it is
- The substrates, solder and bonding materials, molding compounds, and thermal materials that assemble and protect the die.
- Where it fits
- The back end — connecting the die to the system and sealing it into a package.
- Why it matters
- They carry the die's signals, heat, and mechanical protection; in advanced packaging they increasingly set system performance.
Cleanroom materials
- What it is
- The ultra-pure water, process gases, chemicals, and consumables that keep the fab environment and every step clean.
- Where it fits
- Everywhere — supporting essentially every process step.
- Why it matters
- A single stray particle or trace contaminant can kill a device, so purity and cleanliness are central to yield.
Emerging materials
Soon- What it is
- New materials under research — for example high-mobility channels, 2D materials, and new dielectrics and interconnect metals.
- Where it fits
- At the leading edge, as scaling of conventional materials runs into limits.
- Why it matters
- New materials are one of the main ways device performance can keep improving as classical scaling slows.
Where materials connect
Equipment alone does not manufacture a device. Every result comes from equipment + materials + process conditions + process control + metrology working together — materials are worked by the equipment, shaped by the processes, and sourced through the industry’s supply chain.