Is a PE a process engineer or a product engineer?

The same two letters mean two common things in the chip industry. In a wafer fab, PE usually means process engineer. At chip design companies, test-and-assembly houses and the product groups of many companies, it usually means product engineer. Both work on chips; the difference is scope. One owns a step in the process, the other owns a product.

What does a PE do in a wafer fab?

A chip goes through hundreds of steps, and a fab splits them into areas such as lithography, etch, thin film and CMP. A process engineer usually owns a few steps in one area, and the group of tools that runs them:

• Recipes: the recipe a tool runs (gases, pressure, power, time) is theirs; changes and trials go through them.
• Data: every lot's measurements and the control charts. A slow drift should be spotted here first.
• Lot decisions: when a tool fails or a measurement is out of spec, should the lot move on, go on hold, be reworked or scrapped? They give the call, often together with the process integration engineer.
• Improvement: running experiments to make the step more stable and cut defects.

University career guides describe it the same way: owning a manufacturing step or a set of tools, and using experiments to improve yield, throughput and stability.

What does a PE do at a chip design or test company?

A product engineer follows one chip from start to finish. Once wafers are made and tested, the data comes back to them:

• Test data and yield: results from wafer sort and final test, what share is good, which bin the failures land in, and where on the wafer map they cluster.
• Tracing causes: when yield drops, they judge whether the problem looks like design, process, packaging or the test itself, then bring in the right people.
• Moving to volume: as a new product goes from trial runs to mass production, they help set what is tested and where the limits sit, often with the test engineer.
• Customer issues: when a customer sends failed parts back, they find out why and explain it.

A university lecture on process development puts product engineering at the end of the line: it reads final test data and electrical parameters to drive yield, and feeds the results back to manufacturing.

Do the two PEs ever meet?

Yes, and usually over yield. A product engineer sees a lot's yield drop, with the failures all near the wafer edge, traces it back to one step, and ends up talking to that step's process engineer, often through the process integration engineer (PIE). The process engineer checks their own measurements and control charts for that period. One looks back from the result, the other looks forward from the source; when the two sets of data line up, the cause turns up.

How do you tell which PE someone means?

• Where they work: in a wafer fab, PE is usually process; at a design company, a test-and-assembly house or a product group, it is usually product.
• What they talk about: "this tool's recipe" or "this step's control chart" means process; "this chip's yield", "which bin" or "the customer" means product.
• The full title: Process or Product.

A few abbreviations you will hear with them: EE is the equipment engineer (at university, EE is electrical engineering), PIE is process integration, TE is the test engineer, and QA or QE is quality. Titles and the split of work differ between companies; this is the common pattern.

In fab24hr

In fab24hr, PE means process engineer. On the night shift, you are the one woken by the phone at 02:47: ETCH-03 has stopped, and you decide whether the wafers stuck inside can be saved and whether the lots behind them can move. A product engineer appears too: Leo, who phones with questions about numbers in some shifts at the test-and-assembly house and on the R&D line, is the customer's product engineer. The companies, tools, lot numbers and people in the game are fictional; what the two kinds of PE do comes from public, general sources. For how a PE and an equipment engineer split the work, read What's the difference between a process engineer and an equipment engineer?.