What departments does a chip fab have, and who talks to whom every day?

The common departments in a chip fab are roughly these groups: Manufacturing keeps lots moving from step to step, process engineering owns whether each step comes out right, equipment engineering looks after the tools, process integration owns whether the whole flow fits together, yield and failure analysis find where chips fail, QA makes sure what leaves the fab can be trusted, Production control plans when each lot finishes, and Facilities runs the water, power, gases and chemicals. Alongside them are IT and automation and environment, health and safety (EHS). Companies split and name these differently; this is a common, general split. This article doesn't retell each job. It shows how they connect. For the full list of roles, see What jobs are there in the semiconductor industry?

Why so many departments?

A wafer goes back and forth between areas such as litho, etch and thin film, through hundreds of steps, over weeks to months (see What do the seven process areas of a chip fab do?). How to fix a tool, how to set a condition, which lot goes first, how to keep the water, power and gases running: no one person can know it all, so the work is divided.

Think of a big hospital. Nurses, doctors, the lab, the pharmacy and the maintenance crew each look after one part, but the patient is the same person, and every handoff has to be clear so nobody slips through. In a fab, the patients are the lots of wafers.

What does each department look after, and who do they talk to most?

Department	Looks after	Talks to most each day
Manufacturing, and the technicians on the line	Lots moving on time: dispatch and tracking; running tools by the SOP	Equipment (when is the tool back), Process (can this lot go on), Production control (which lots first)
Process engineering	The recipes and measurements for a few steps in one area, and whether a lot can go on	Equipment, Manufacturing, Integration
Equipment engineering	The tools themselves: maintenance, repairs, parts	Process (a fixed tool needs a qual run), Manufacturing (when is it back), Facilities
Process integration	Whether hundreds of steps, put together, make a chip that works	Process in every area, yield, QA, the customer's engineers
Yield and failure analysis	Where yield is lost, from test data and wafer maps; opening up failed chips to find out what broke	Integration, Process
QA	Whether what leaves the fab can be trusted: outgoing inspection, following incidents to the end, audits	Manufacturing, Integration, customers
Production control	How many wafers to start, which lots go first, when they ship	Manufacturing, sales
Facilities	Water, power, gases, chemicals, air conditioning, exhaust	Equipment, EHS
IT and automation	The MES that records where every lot is, the OHT that carries lots, the links between tools and computers	Manufacturing (if the system drops, lots can't move out), Equipment
EHS	Safe handling of chemicals and gases, training, emergency response, whether emissions meet the rules	Facilities, Equipment, everyone who comes in to work

Each job's own day: What does the manufacturing department do in a chip fab?, What's the difference between a process engineer and an equipment engineer?, What does an equipment engineer do in a chip fab?, What does a process integration engineer (PIE) do?, What is failure analysis (FA)?, What does QA (quality assurance) do in a chip fab?, What does production control do in a chip fab?, What does a fab facilities engineer do?.

When something goes wrong, who does what?

Say a step has just finished and the metrology tool finds the line width out of spec. What follows is a relay:

1. Manufacturing and the technicians stop the lot: following the OCAP, they put the lot on hold, stop the tool if it has to stop, and call the on-call engineer. Stopped now, a bad lot doesn't go one step further.
2. Process and Equipment investigate together: Process first checks it isn't a measurement error, then looks at when the control chart started to drift and which other lots ran on the same tool, and stops those too (containment). Equipment looks at the tool's logs and parts. The cause could be in the conditions or in the hardware; looked at separately, each side sees only half. Once it's fixed, Equipment does the tool handback and Process runs the qual run; the tool release comes only when both pass.
3. Integration looks downstream and decides each wafer: whether the drift will affect later steps and the final electrical results takes someone who sees the whole flow. Wafer by wafer, they decide: continue, rework or scrap. This is disposition.
4. QA checks the decision followed the rules: is it recorded, has the deviation been signed by the right people, does the customer need to be told. QA often looks at this together with Integration. No one person decides alone, so later anyone can see who let the lot go on and why.
5. Production control replans: how late this lot will be and how to order the lots behind it. If a due date moves, sales tells the customer.
6. Everyone writes the review: each section of the incident report needs facts that sit with different people. What happened is in the tool and MES records, containment comes from the list Manufacturing pulls, the impact comes from Integration's disposition, and the cause comes from the people who use that tool every day. Every countermeasure needs an owner and a date.

Sometimes every department's own records are right and the problem sits in the handoff to the next person. That's why reviews often put everyone in the same room. For the details of each step, see What is a lot hold?, What does OCAP mean in a chip fab? and What is root cause analysis?

What gets passed on at handovers and daily meetings?

A fab runs around the clock (see Why do chip fabs run 24 hours a day?), so work changes hands every day. A handover passes on what isn't finished: which tool is down, which lot is on hold, and who decides. For why handovers matter so much, see What's the difference between a fab technician and an engineer?

Work changes hands at more than shift change. Equipment hands a repaired tool back to Process; the R&D line hands a stable process to the production fab, after a transfer review (see How is an R&D line different from a production fab? and What is new product introduction (NPI)?); finished wafers go to the test-and-assembly house. Each of those is a handover too.

Many fabs also hold a regular daily meeting: what happened overnight, which tools are down, where the hot lots are, and who owes whom an answer by what time today. A bigger incident gets its own review meeting. What matters is that every item leaves the room with an owner.

Which department matters most?

None can be left out. Without Manufacturing, lots don't move; without Equipment, tools sit idle; without Integration, every step can be right and the chip still may not work; without Facilities, the building has no water or power. Each looks after a different side of the same wafers.

In fab24hr

Most of the roles in fab24hr are these departments. Tap "Clock in", choose "A day in the fab", then on the "Your role today" card tap "Production fab" and swipe: process and equipment engineers in seven areas, Manufacturing, the process integration engineer, the facilities engineer, the quality engineer, Production control and the mask engineer. "R&D line" has the R&D integration engineer, R&D process engineers and the vendor field service engineer; "Test-and-assembly house" has the test engineer, the assembly process engineer and the customer liaison.

The role where you see most clearly who talks to whom is the etch process engineer (tap "Production fab", swipe to the process engineer, then tap "Etch" under the name). At 02:47, Hao from Manufacturing's night shift calls you at home: the tool is down. At the morning meeting you promise the chief a 10:30 update on the cause, the time the tool comes back and what happens to the lots, and none of it is in your hands: you ask Kai in Equipment and Ya-Ting in Integration, then tell Yun in Manufacturing when she can send lots in. In the afternoon the incident report has four sections; what happened is in the tool records, and the other three are with three people. At the 16:30 review meeting, every department speaks from its own data, every record is right, and the department manager asks: then where did it go wrong? Chapters 6 to 9 of the main story, The life of a chip, are this same day.

Yield, failure analysis, IT and EHS have no roles; sometimes a tool loses its link to the system and IT's on-call calls you. For a timetable of several roles through one day, see A day in the life of a fab engineer. The companies, people, tool numbers and lot numbers in the game are fictional; how departments split the work and who does what when something goes wrong come from public, general sources, and real names and splits differ between companies.