X-ray Lithography System by Substrate: status and timeline

Milestones

Next · Prototype lithography tool development

Founded2022Complete.
Emerged from stealth with Series A fundingOct 2025Complete.
Prototype lithography tool developmentTarget 2026Current milestone.
US fab constructionTarget 2026Not yet reached.
First production runTarget 2028Not yet reached.

Most important updates

Substrate emerges from stealth with $100M Series A to build US X-ray lithography fabsOct 2025

Upcoming

2026Prototype lithography tool development (next)
2026US fab construction
2027Initial test wafers
2028First production run
2028Commercial production begins

Current obstacles

New materials neededPhotoresists and optical materials must be developed specifically for X-ray lithography.
Manufacturing-scale reliabilityAccelerators must operate reliably 24/7 for fab production, requiring significant engineering improvements.
Capital and fab constructionBuilding a leading-edge fab requires billions in capital and multi-year construction.

Physics limits

Diffraction physicsEven at short wavelengths, diffraction limits how small features can be printed; below 1nm becomes physically challenging.
X-ray generation efficiencyMost electron energy is lost as heat in X-ray production; higher throughput demands more power and cooling.

How it works

3 parts

Acceleration

Electron acceleration

Radio-frequency cavities accelerate pulses of electrons to high energy, riding successive RF waves.

X-ray generation

X-ray emission

High-energy electrons generate intense X-ray light, used to expose photoresist on wafers.

Patterning

Single-pass lithography

X-rays expose resist in a single pass, avoiding the multi-exposure process required by EUV lithography.

Spec sheet

Spec	X-ray Lithography System
Target manufacturing node	2nm and below^R (reported)
Light source	Radio-frequency cavity accelerator generating X-rays^R (reported)

^R reported by the company

Update log

1 update

Oct 2025

Major: Substrate emerges from stealth with $100M Series A to build US X-ray lithography fabsPressFunding

About Substrate

The team behind X-ray Lithography System

Substrate

X-ray lithography, semiconductor fab, accelerator, 2nm and below

Substrate develops X-ray lithography as an alternative to traditional EUV for advanced chip production. Founded 2022; emerged from stealth October 2025 with $100M Series A at $1B+ valuation. Shifting from selling tools to building US fabs targeting 2028 production.

Uses particle accelerators to generate X-rays for lithography at 2nm and below, without ASML's EUV infrastructure constraints.
October 2025: emerged from stealth with $100M Series A, shifted from selling tools to building its own US foundries.
Unicorn at $1B+ pre-revenue; building production-quality lithography tools and planning US fab construction.

substrate.com (opens substrate.com)Company profile →

Founded: 20224 yrs
Headquarters: United States
Status: Private
Valuation: $1BprivateOct 2025
Raised: $100M1 round
Last round: Series A · $100MOct 2025
Works in: ComputingChipmaking tools
Coverage: 1 program · 1 updatelatest 1 Oct 2025checked 10 Oct

Spec

X-ray Lithography System

Target manufacturing node

2nm and below^R (reported)

Light source

Radio-frequency cavity accelerator generating X-rays^R (reported)