The semiconductor supply chain is the sequence of steps that turns a chip design into a tested device delivered to a manufacturer. The main stages are design, wafer fabrication, assembly and packaging, testing, and distribution. Each stage needs specialised equipment, materials and expertise, and many are carried out by different companies in different places.
That specialisation makes the chain efficient at scale and slow to adjust. Building new capacity takes years, so a mismatch between supply and demand can last far longer than in most industries.
The main stages
- Design. Engineers define the circuit, using design software and licensed building blocks of intellectual property. Companies that only design chips are often called fabless.
- Wafer fabrication. Circuits are built layer by layer on silicon wafers in highly controlled cleanroom plants called fabs. This is the most capital-intensive step.
- Assembly and packaging. Wafers are cut into individual dies, which are mounted in packages that protect them and connect them to circuit boards.
- Testing. Devices are tested for function and reliability, both at wafer level and after packaging.
- Distribution. Finished chips move to device makers, either directly or through distributors who hold stock for smaller buyers.
Who does what
| Business model | What it does | Supply chain implication |
|---|---|---|
| Integrated device manufacturer | Designs and manufactures its own chips | Controls more of the chain but carries heavy capital cost |
| Fabless company | Designs chips and relies on others to make them | Depends on foundry capacity and allocation |
| Foundry | Manufactures chips designed by customers | Capacity is shared among many customers |
| Outsourced assembly and test provider | Packages and tests finished wafers | Adds another handoff and lead time |
| Equipment and materials suppliers | Provide tools, wafers, gases and chemicals | Few qualified sources for some critical items |
Why shortages are hard to fix
- Long lead times. Production of a chip passes through many process steps, and orders are placed months ahead.
- Capacity cannot be added quickly. New fabs and equipment take years to plan, build and qualify.
- Specialised inputs. Some equipment and materials come from very few suppliers.
- Qualification requirements. A customer cannot easily switch chips or sources, because the part is designed into a product and must be validated again.
- Demand swings. Chips are used in many industries, and orders can rise or fall sharply, which makes planning difficult. The bullwhip effect, where small demand changes amplify upstream, is a common explanation for overordering and later surpluses.
- Geographic concentration. Some steps are concentrated in a small number of regions, so a local event can affect global supply.
Planning approaches buyers use
Companies that buy chips can reduce exposure even when they cannot control supply. Long-term supply agreements, forecasts shared early with suppliers and selective safety stock for critical parts are common. Design teams can also favour parts with more than one source or with compatible alternatives. These choices cost money, so they are usually applied to parts whose absence would stop production.
- Identify which chips are single-source or have long lead times.
- Share rolling demand forecasts with suppliers and distributors.
- Check last-time-buy and end-of-life notices.
- Verify authenticity when buying on the open market, since counterfeit parts are a recognised risk.
- Record where a part was made, to support traceability.
Where analytics and AI help
Within factories, analytics is used for yield analysis and equipment monitoring. Across the supply chain, forecasting tools and supplier risk monitoring can highlight parts that are likely to become constrained. These tools cannot add capacity, and their output depends on how much supplier data is shared, which is limited in this industry.
Common questions
What does fabless mean?
A fabless company designs semiconductors but does not own a fabrication plant. It contracts a foundry to manufacture the chips.
Why can’t companies just build more fabs?
Fabs require very large investment, specialised tools with long delivery times and skilled staff. Even after construction, processes must be qualified before volume production.
What is the role of distributors?
Distributors hold inventory, break bulk quantities down and give smaller customers access to parts. They also provide a channel for stock in tight markets.
Sources and further reading
- MIT Center for Transportation and Logistics (MIT CTL)
- Council of Supply Chain Management Professionals (CSCMP)
- Harvard Business Review: Supply Chain Management topic (Harvard Business Review)