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Semiconductors 101: a free course following the life of a chip

For anyone who wants to learn about semiconductors from zero

A free syllabus that follows the life of a chip: from what the semiconductor industry does, through how a fab builds a chip layer by layer and how it knows it was done right, to the people who work there and the future. Each unit has one or more plain-language articles, a chapter or shift of the game fab24hr, and discussion questions with no single right answer; most units on the fab and on packaging and testing also have a 3D machine you can take apart. No install, no sign-in; you can read and play it all on a phone.

Part 1: What semiconductors do

  1. 1What semiconductors and chips are
  2. 2Transistors: tens of billions of switches
  3. 3The supply chain: who does what, and how they work together

Part 2: Before a chip is born

  1. 4Needs, specs and IC design
  2. 5Masks and tape-out: how a design becomes a mask set

Part 3: Inside the fab

  1. 6Wafers and cleanrooms
  2. 7How chips are made: the big picture
  3. 8Wet clean: washing wafers between steps
  4. 9Furnace: oxidation and annealing in the heat
  5. 10Thin film: building up layer by layer
  6. 11Lithography: printing the pattern
  7. 12Etch: cutting the pattern in
  8. 13Doping: ion implant and annealing
  9. 14Wiring and polishing: CMP and layer upon layer of metal
  10. 15Process integration: putting hundreds of steps in order
  11. 16A factory that never stops

Part 4: How do you know it was done right?

  1. 17Metrology and inspection: what to measure, and how many wafers
  2. 18Control charts and daily monitoring
  3. 19Yield and wafer maps
  4. 20When something goes wrong: from the alarm to "never again"

Part 5: After the wafer is finished

  1. 21Packaging and testing
  2. 22Reliability, shipping and building chips into products

Part 6: People and teamwork

  1. 23The people in a fab: roles, shifts and careers
  2. 24From R&D to production: who goes first, and how the handoff works

Part 7: The future

  1. 25How small can transistors get? The story of "nanometers"
  2. 26Advanced packaging and new materials: more than shrinking
  3. 27Making sense of chip news

Part 1: What semiconductors do

What a chip is, what the switches inside it, up to tens of billions, do, and what each part of the industry, from upstream to downstream, does and how they work together.

Unit 1What semiconductors and chips are

"Semiconductor" often means both a material and a whole industry. Start by sorting out the words people mix up most: semiconductor, wafer, chip and integrated circuit.

Goals

Think

  1. Which things around you contain chips? If the world had half as many chips tomorrow, where would your day get stuck first?
  2. A chip is finished by several kinds of companies sharing the work, not by one company from start to finish. What does that division of labor gain, and what risks does it bring?

Lesson notes and slides →

Unit 2Transistors: tens of billions of switches

A chip can compute and remember because it holds a great many tiny switches controlled by electricity; a phone chip has more than ten billion. This unit goes from a single switch to processors and memory.

Goals

Think

  1. A phone left alone still slowly loses charge. Where does the energy go? Try to explain it with what you read in this unit.
  2. One kind of memory forgets when the power is cut; another remembers. Why does a phone need both? Can you think of a similar division of labor in everyday life?

Lesson notes and slides →

Unit 3The supply chain: who does what, and how they work together

On its way from materials, design, masks and the wafer fab through assembly and test to the inside of a phone, a chip often passes through several companies. First see what each stop does and why it is often a different company, then follow one order from choosing a process to the wafers arriving at the test-and-assembly house.

Goals

Think

  1. A foundry often makes chips for several competing companies at once. If you ran a small design company, what would you want to ask before handing over your most valuable asset, the design?
  2. For a first chip, you can share a ride on a multi-project wafer (MPW), or make your own full mask set right away. If it were your call, what would you look at, and what does each choice cost you?

Lesson notes and slides →

Part 2: Before a chip is born

How a chip goes from a need to a design that is sent out to be made into photomasks, before it ever reaches the fab.

Unit 4Needs, specs and IC design

Before a chip goes into a fab, it is designed in full on computers and checked many times: a large chip has more than ten billion transistors, far too many to draw or check by hand, so every step relies on design software, and some blocks are even bought. Every step from "what should it do" to handing over the design is there to avoid finding a mistake after tape-out.

Goals

Think

  1. A small hearing-aid company is designing its own chip for the first time. The analog circuit that turns the microphone's sound into numbers and the clock circuit that sets the beat for the whole chip could be drawn in-house or bought as ready-made IP. How would you decide which to do yourself and which to buy? What would you ask the seller before buying?
  2. Verification takes a lot of people and time, but doing less of it risks finding a mistake after tape-out. If the schedule were tight, how would you decide that "this is enough checking"?

Lesson notes and slides →

Unit 5Masks and tape-out: how a design becomes a mask set

Handing a checked design to the fab is called tape-out, and changing it after that means new masks. The design can't be printed as it is either: it first has to be corrected and made into a set of photomasks. A mask is the "negative" for exposure, and one printable spot or one small error on it prints in every field of every wafer, so it has to be drawn extremely accurately and checked extremely closely.

Goals

Think

  1. The finer the OPC, the bigger the mask data and the longer and more expensive the mask; the more conditions it's checked under, the longer the computers have to run. But a pattern that is only right under ideal conditions can fail in production. If the tape-out date were tight, which layers and which places would you spend the time on, and why?
  2. One spot on a mask prints in every field, so masks are taken down and inspected after a while. Check too often and the mask spends more time out of use; check too rarely and a problem may only be found once it has grown. If you set the schedule, how would you balance it, and what would you look at?

Lesson notes and slides →

Part 3: Inside the fab

How a wafer becomes chips step by step: what each step does, why it is done that way, and what goes wrong if it isn't.

Unit 6Wafers and cleanrooms

Chips are made on a round silicon wafer, inside a very clean cleanroom. Why round? Why ever larger? And how clean is clean enough?

Goals

Think

  1. A fab uses a lot of water and electricity, and it matters to the economy. If you lived near one, what would you care about? What would you ask the company to explain?
  2. In a cleanroom, people are the biggest source of particles. If you wrote the rules for going in and out, which three rules would you set, and why?

Lesson notes and slides →

Unit 7How chips are made: the big picture

A wafer goes through hundreds of steps over several months in a fab. Look at the whole map first; the next units zoom in one area at a time.

Goals

Think

  1. Why is a chip built by repeating "deposit, print, etch" layer after layer rather than all at once? Try explaining it with house building or another everyday example.
  2. A wafer spends months in the fab. Over such a long process, where do you think the biggest risk lies, and how could it be caught early?

Lesson notes and slides →

Unit 8Wet clean: washing wafers between steps

Every step leaves something invisible on the wafer surface, and the next step needs a clean surface. Cleaning is one of the most repeated steps in the whole flow: clean too little and the next layer grows badly; clean too much and what's eaten away can't be put back.

Goals

Think

  1. A batch tool cleans many wafers at once; a single-wafer tool cleans one at a time and is less likely to carry dirt from one wafer to the next. If you had to choose one for a certain step, what would you ask first?
  2. A cleaned wafer has a time limit, but the next tool may go down, be in maintenance, or have hot lots queued ahead. Should the next lot be cleaned now? What does each choice cost?

Lesson notes and slides →

Unit 9Furnace: oxidation and annealing in the heat

In many processes, the very thin insulating layer under a transistor's gate is grown in a furnace, and implanted atoms only start to conduct after heating. But every heating moves what was made before a little more, so the heat has to be counted from start to finish.

Goals

Think

  1. A furnace load of a hundred wafers is efficient, but if that load goes wrong, the loss is large too. In your own life or work, when would you do many at once, and when would you rather do one at a time? Why?
  2. A furnace run stops halfway. Rerunning the whole step spends a whole extra step's worth of thermal budget; holding the lots, measuring the monitor wafers and running only what's left takes more time. If it were your call, what would you want to know first?

Lesson notes and slides →

Unit 10Thin film: building up layer by layer

Almost every layer of a chip starts with a new film of material, so that there is something to print and etch. How thick, how even and how clean the film is carries on into etch, polishing and the next litho step.

Goals

Think

  1. Which do you think is harder to control, how thick a film is or how even it is? If it is thicker in the middle than at the edge, what problems might later steps run into?
  2. A film a little thicker or thinner changes what comes out of CMP, the next step. If you were the thin-film engineer, what would you tell the next step before they ask, and why?

Lesson notes and slides →

Unit 11Lithography: printing the pattern

Lithography (litho) decides how fine a chip's patterns can be. It is one of the most precise steps, and the most advanced lithography machines are extremely expensive.

Goals

Think

  1. Before the next layer is printed, it has to be aligned to the one below; a tiny miss can ruin the whole wafer. What in your own life has to line up with the layer before it? What happens if it's off, and how would you check that it lines up?
  2. The most advanced lithography machines are extremely expensive. What might a machine that costly mean for the price of chips, and for who can afford to make the most advanced ones?

Lesson notes and slides →

Unit 12Etch: cutting the pattern in

Litho only prints the pattern onto the photoresist; the material underneath hasn't been touched yet. Etch is what really cuts the pattern into the wafer, and a mistake there is hard to undo.

Goals

Think

  1. Endpoint detection says the layer is through, yet the tool keeps etching a little longer: too short and some holes don't open, too long and the layer below is damaged. If you had to set how long, what data would you look at first?
  2. A tool fails at night with a wafer stuck inside, half etched. What does waiting for more information cost, and what does acting right away cost? (Think about it after playing chapter 6.)

Lesson notes and slides →

Unit 13Doping: ion implant and annealing

Very pure silicon barely conducts. A chip needs "this small region conducts, the one next to it doesn't", so a tiny amount of other atoms has to go into the right places, at the right depth.

Goals

Think

  1. A wrongly implanted wafer looks exactly like a good one and may not be caught for a long time. If you were the one checking line by line before the lots go in, how would you make sure you don't miss a line? Who should check it again with you?
  2. An anneal has to be hot enough, but not too long. When "a bit more is safer" and "too much does harm" are both true, how would you decide where to stop?

Lesson notes and slides →

Unit 14Wiring and polishing: CMP and layer upon layer of metal

Transistors are only useful once layers of metal wiring connect them. How the wiring is dug, filled with copper and polished flat decides whether current gets through, and how fast the chip runs.

Goals

Think

  1. A polishing pad gets smoother with use, so the same time removes less and less. What does stopping for two hours to change the pad cost, and what does lengthening the polish time to get by cost? Who is affected either way?
  2. The film from the step before came out a little thicker, still within spec, and what CMP polishes off changes with it. Between the two steps, who should notice first, and who should speak up first?

Lesson notes and slides →

Unit 15Process integration: putting hundreds of steps in order

Every step can be done right and the chip still may not work: hundreds of steps have to be put in one flow, and someone has to watch how they affect each other from start to finish.

Goals

Think

  1. Changing one condition makes this step better but may make a later step worse. Who should have the say over whether to change it? What data should they see before deciding?
  2. The tool at the next step suddenly stops while a lot's Q-time is counting down. What does waiting for the repair cost, and what does redoing the step before cost?

Lesson notes and slides →

Unit 16A factory that never stops

A fab never turns off the lights: wafers ride in sealed boxes along tracks in the ceiling, some steps cannot wait too long between them, and hot lots and machine maintenance all have to fit in.

Goals

Think

  1. Shift work keeps the factory running, but people need sleep. How should a factory that never stops look after the people who work in it?
  2. When a hot lot jumps the queue, the lots in front have to wait. Should hot lots always go first? Who decides, and on what basis?

Lesson notes and slides →

Part 4: How do you know it was done right?

How a fab measures, watches its numbers every day and counts its yield, and how it deals with a problem step by step.

Unit 17Metrology and inspection: what to measure, and how many wafers

A wafer goes through hundreds of steps over weeks to months before it can be powered up and tested. Finding a mistake only then is far too late, so each important step is checked as soon as it is done.

Goals

Think

  1. Measuring more is reassuring; measuring less keeps lots moving. If a tool you look after has been a little unsteady lately, how would you decide how many more lots to measure? Who would you talk to first?
  2. "Compare with the chip next door" can't find a problem every chip shares. In your own life or work, is there a mistake you can't see because everything has it? How would you find it?

Lesson notes and slides →

Unit 18Control charts and daily monitoring

A measured number only means something next to a yardstick that says whether the process is still behaving as usual. The control chart is that yardstick: it shows a process changing before anything has been made wrong.

Goals

Think

  1. The control chart says "still within spec, but no longer normal", and the lot is waiting. If it goes on to the next step, who pays? If it stays held, who pays?
  2. Control chart rules and FDC thresholds catch problems earlier the tighter they are, and raise more false alarms too; set them too loose and slow decline goes unseen. If you were setting them, where would you draw the line? Will someone called out by false alarms many times still look carefully next time?

Lesson notes and slides →

Unit 19Yield and wafer maps

What a fab finally hands over is good chips. Yield says what share is good, a wafer map says where the bad ones are, and only the two together tell you which step to go back and look at.

Goals

Think

  1. Yield rises from 90% to 95%. What does that mean for the fab, for the company buying the chips, and for the people using the product?
  2. Failures on a wafer map form a grid: it could be the mask, or it could be the probe card. How much effort would each take to check? Which would you check first, and why?

Lesson notes and slides →

Unit 20When something goes wrong: from the alarm to "never again"

Even the most careful fab has problems. What makes the difference is whether, in those first minutes, things are done in the right order, and whether afterwards the holes that let the mistake through get closed.

Goals

Think

  1. At three in the morning a tool lights red, a lot is waiting, the engineer is asleep, and the person next to you says one reset usually does it. What does calling per the OCAP cost, and what does trying it first cost?
  2. Think of a small mistake you keep making, such as leaving home without your keys. If you don't blame your own carelessness but look for "what makes this easy to forget", how would you change things so it can't happen or can't be forgotten?

Lesson notes and slides →

Part 5: After the wafer is finished

Once the wafer leaves the fab: how chips are tested and packaged, how they are shown to last for years and the weak ones screened out, and how they are packed, shipped and soldered onto circuit boards to go into the products in your hands.

Unit 21Packaging and testing

A finished wafer is not yet a usable chip. It is tested, cut apart, connected, sealed in a package and tested again before it goes into a product.

Goals

Think

  1. More testing means more reliable chips, but also more cost and time. If you were responsible for a hearing-aid chip, how would you decide how much to test?
  2. Why do some companies specialize in packaging and testing instead of leaving it all to the fab?

Lesson notes and slides →

Unit 22Reliability, shipping and building chips into products

Testing only asks whether a chip is good "right now", but it has to work inside a product for years. This unit looks at how a few weeks can tell you about years from now, how weak chips are screened out, and how chips are packed, shipped and soldered onto circuit boards to end up in the products in your hands.

Goals

Think

  1. The batch ships tomorrow morning. The reliability lab offers to take a few hundred chips and run them powered at high temperature for two days to check for early-life failures, but the whole batch would ship a week late. If the decision were yours, what would you want to know first? And who would you talk to first?
  2. The caution label on a moisture barrier bag is just a few boxes of text: the level, the seal date, how long you have to solder the parts after opening. If you loaded parts onto the machines at an assembly plant, how would you make sure every bag is handled that way? If one box were left empty, who would run into trouble, and when?

Lesson notes and slides →

Part 6: People and teamwork

Who works in a fab and how the shifts run, and who does what, in what order, as a new chip goes from R&D to mass production.

Unit 23The people in a fab: roles, shifts and careers

A fab is not just machines. This unit looks at its departments, who talks to whom every day and who does what first when something goes wrong, then at the jobs inside and what shift work and being on call involve.

Goals

Think

  1. A machine fails in the middle of the night. Who should be woken up? What does waking someone cost, and what does not waking them cost?
  2. At the same moment, say when a machine goes down, what are process, equipment and Manufacturing each worried about? Which role would you most and least like to have, and why?

Lesson notes and slides →

Unit 24From R&D to production: who goes first, and how the handoff works

A new chip, from the first time it's made in a fab to steady high-volume shipments, passes through several legs: design, the fab, test, reliability, the customer and the production fab. This is new product introduction (NPI). A new process generation, or a chip that needs new steps, is also often made and made stable on the R&D line first. Each leg is taken over by different people, and how clear the handoff is decides how well the next people can do their job.

Goals

Think

  1. The reliability tests haven't finished, but the customer wants wafers started in the production fab now (a risk start): if the tests pass, the customer gets parts sooner; if they fail, the lots started early may all be scrapped. In your place, how would you explain the cost of each side to the customer?
  2. Work instructions are written for someone who may never have trained on the R&D line. How detailed do you think they need to be so that someone following them doesn't go wrong? What can't be passed on in writing alone?

Lesson notes and slides →

Part 7: The future

How small transistors can still get, and the other roads taken alongside shrinking: changing the transistor's shape, moving power lines to the back of the wafer, stacking upward, joining several chips in advanced packaging, other semiconductor materials, and light to carry data, several of which have to do with the "memory wall" (processors compute fast, but data can't arrive fast enough); and finally how to read chip stories in the news.

Unit 25How small can transistors get? The story of "nanometers"

The news talks about "2 nm" and "3 nm" every day. Once you know where the number comes from, why each shrink gets harder and why transistors keep changing shape, you can see where chips are heading next.

Goals

Think

  1. A newer generation usually does the same work on a bit less power, or a bit faster on the same power, but it is also harder and more expensive to make. If you were making a chip that runs on a single button cell, would you go for the newest generation? What would you ask before deciding?
  2. Process names stopped being real sizes long ago, yet each new one is still roughly the last one times 0.7 (with some half-steps in between). What is good about naming them this way, and what does it lead people to misunderstand? If it were up to you, how would you name them?

Lesson notes and slides →

Unit 26Advanced packaging and new materials: more than shrinking

Processors compute faster and faster, but memory can't deliver data fast enough to keep up, and this "memory wall" often leaves AI chips waiting. Stacking memory right next to the processor, packaging chips together and sending data over longer distances as light all have to do with it; add new materials, and once you know these roads, the new terms in the news start to fit together.

Goals

Think

  1. Splitting a big chip into chiplets may improve yield and put the money where it matters most; but it needs extra room for connections, the packaging gets harder, and if one piece inside is bad, the whole set is wasted. If it were up to you, what kind of chip would be worth splitting? What kind would you keep in one piece?
  2. To get past the memory wall, you can add more cache or put more HBM stacks beside the processor, and some researchers are working on computing inside the memory; every road has a price. If you were building a machine that only answers questions with AI, which road would you spend money on first? What would you want to know before deciding?

Lesson notes and slides →

Unit 27Making sense of chip news

"Mature-node shortage", "AI chips", "a major breakthrough": with what you have learned so far, you can read these headlines and spot where they jump too fast.

Goals

Think

  1. Find a recent chip news story and retell it to someone at home in three plain sentences. Which words did you learn in this course? How far along is what it describes: made in research, in mass production, or already widespread? Which claims seem exaggerated or unclear?
  2. What kind of chips do a car, a phone and an AI server each need? If you could add only one more production line, which would you build it for first? Why?

Lesson notes and slides →

Suggested assignments (open-ended, no single right answer)

  1. The life of a chip: draw a flow chart from design to finished product. Mark the three places you think are most likely to go wrong, and the step at which a problem there is usually discovered.
  2. A handover note: after playing a shift, write a handover note for the next shift: what happened, what you decided, and what is still open. Swap with a classmate and see whether they could carry on from it.
  3. Chip news in plain words: rewrite a chip news story in three plain sentences for someone who has never studied this, and mark anything in the original that seems exaggerated or unclear.
  4. Same moment, different people: in groups, each member plays the same shift in a different role. Compare what each role saw and feared when the machine went down, and write it up in one page.
  5. Find the simplification: pick a passage from a required article, compare it with a textbook or university lecture notes, and write down what the article simplified and whether the simplification is reasonable.

Level and accuracy

No physics or chemistry background is needed; middle-school science is enough. The aim is to understand the flow, the division of labor and the trade-offs, not to learn to operate machines.

The articles are written from public textbooks, industry standards, university course notes and papers, and checked again after writing. To stay readable, some things are simplified: analogies instead of equations, and "about" in front of many numbers. To go further, pair them with two kinds of textbook: semiconductor devices (why it works) and semiconductor manufacturing processes (how it is made). If you spot a mistake, use "Spot a mistake? Report it" at the end of each article.

The companies, people, machine numbers, lot numbers and figures in the game are fictional, do not represent any company's actual practice, and are not operating training. What is real is the shape of the work: shifts, handovers, time limits between steps, test runs, and following procedures when something goes wrong.

Citing and classroom use

This outline, the articles, the machine clips and pictures, and the worksheet are free to use in class and for non-commercial teaching: on screen, in handouts, printed for students. Please credit fab24hr. Do not sell them or present them as your own work.

To cite it, for example: "Semiconductors 101: a free course following the life of a chip." fab24hr, October 2026. https://fab24hr.com/en/learn/

To use the game in a single lesson: fab24hr in the classroom has 20-, 40- and 50-minute plans; the worksheet prints as it is; Chip fab machines, taken apart links to all 31 machines, with QR codes.

Questions people ask

Is this a formal course? Does it cost anything or need sign-up?

No cost and no sign-up. It is a free syllabus: each unit links to plain-language articles on this site and a chip fab game that runs in the browser, and most units on the fab and on packaging and testing also link to 3D machines you can take apart. There are no exams or certificates, and teachers can change the order and the amount to fit their course.

Can I follow it without a science background?

Yes. The articles are written for complete beginners, every piece of jargon is explained in plain words, and middle-school science is enough. The aim is to understand the flow, the division of labor and the trade-offs; to go further, add textbooks on semiconductor devices and on manufacturing processes.

Is it available in other languages?

Yes. This outline, the articles and the game are in Traditional Chinese, English and Japanese: the Chinese version is at fab24hr.com/learn/ and the Japanese one at fab24hr.com/ja/learn/.

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