Apple has not shipped an InFO-PoP with side-by-side integrated die yet. This is expected to be the first one, using RDLs for the die-to-die interconnect (so different than M-Ultra series that uses silicon bridges).
The terms to search for are fan-out wafer level packaging (FOWLP) and TSMC InFO. The chiplets come from different wafers and are reconstituted into a molded plastic wafer, allowing multiple die side-by-side. Then multiple layers of wires are built on top, terminating in a BGA.
Equipment for ion implantation already includes mini accelerators [1] [2]. The semiconductor equipment industry in general has many machines that feel like they came out of a physics lab into a semi fab. For example, plasma dry-etching or deep-reactive ion etching. EUV litho is just one of many very interesting problems--currently the bottleneck so it's talked about a lot.
You are absolutely correct that design costs swamp mask costs by far. For 7 nm, it costs more than $271 million for design alone (EDA, verification, synthesis, layout, sign-off, etc) [1], and that’s a cheaper one. Industry reports say $650-810 million for a big 5 nm chip.
Keep in mind, a semiconductor fab has hundreds of other machines and equipment involved, and US companies are some of the biggest suppliers (Applied Materials, Lam Research, KLA-Tencor--all multi-billion dollar companies).
Lithography is definitely key, but all the equipment and process must work together.
The ASML lithography machine is just one, very important, machine out of many dozens.
A semiconductor fab process involves 100s-1000s of process steps each with dozens to hundreds of parameters.
For example, something as simple as rinsing a wafer after an etch step:
- How long to rinse
- What to rinse with (DI water, solvent, etc)
- What temperature to rinse at
- Should the temperature change over time?
- Agitated vs. non-agitated
It may sound small, but a bad rinse process will tank yields and make the whole process fail.
In a huge semiconductor company like Intel or TSMC, multiple process engineers specialize on each one of these steps out of hundreds. These are truly massive undertakings.