X-ray lithography and a planned US foundry, aimed at ASML's EUV monopoly and TSMC's contract-manufacturing lead.
Semiconductors📍 San Francisco, CAFounded 2022
Current Valuation
$1.0B
as of 2025-Q4
UNICORN
IPO Outlookprivate
Is Substrate going public?
No. Substrate is private and has not filed to go public. There is no S-1 on file.
What is Substrate's valuation in 2026?
Substrate is valued at $1.0B as of 2025-Q4, set by its Series A ($100M, Oct 2025). That is the last confirmed mark, not a live price — private shares do not trade continuously.
Has Substrate filed an S-1?
No public S-1 is on file for Substrate.
Who are Substrate's investors?
Substrate's investors include Founders Fund, General Catalyst, In-Q-Tel, Valor Equity Partners, Allen & Co., Long Journey Ventures.
Answers are derived from the roster record shown on this page — filing status, last round and confirmed marks. Where the record is silent, the answer says so rather than guessing.
Substrate is a San Francisco-based semiconductor company founded in 2022 by British brothers James and Oliver Proud, developing an advanced X-ray lithography system that uses a compact particle accelerator instead of the light source in ASML's extreme ultraviolet (EUV) scanners. It has demonstrated features at 12nm critical dimensions with 13nm tip-to-tip spacing - high-NA EUV territory - and targets 2nm-class nodes and below. Unlike a pure equipment vendor, Substrate does not intend to sell tools to foundries: it plans a vertically integrated US fab network running its own machines, which puts it against TSMC as well as ASML. CEO James Proud, a Thiel Fellow and previously founder of Hello (Sense), has said the aim is mass production by 2028 and leading-edge wafer costs below $10,000 versus roughly $100,000 today, with ASML's most advanced scanners priced above $350 million. The company raised more than $100M in October 2025 at a valuation above $1B - Founders Fund leading, with General Catalyst (which seeded it around 2022), the CIA-backed In-Q-Tel, Valor Equity Partners, Allen & Co. and Long Journey Ventures participating. It remains pre-revenue and its technical claims are contested; the physics of X-ray lithography at production throughput is unproven at scale. Do not confuse Substrate with Source Foundry, a separately funded stealth startup chasing the same ASML-challenger thesis with a different approach.
Company Profile
CEO
James Proud
Founded
2022
HQ
San Francisco, CA
Total Raised
$100M
Growth
Pre-revenue, tool-development phase; targeting mass production by 2028 and leading-edge wafer cost below $10,000 (from an estimated $100,000) by the end of the decade
Last Round
Series A — $100M (Oct 2025) · Lead: Founders Fund
IPO Status
private
Fundraising Status
Series A · $100M · 10 mo ago
privateTotal raised $100M2 disclosed rounds
Series A Impact
Round Size
$100M
Primary financing announced
Post-Money Valuation
$1.0B
Company-announced mark
Round / Post-Money
10.0%
New capital ÷ post-money
Disclosed Funding
$100M
Cumulative disclosed rounds
Step-up compares disclosed post-money valuations. Round / post-money is a financing-size ratio, not an ownership or dilution estimate.
Funding History
Round
Amount
Date
Lead Investor
Post-Money
Series A
$100M
Oct 2025
Founders Fund
$1.0B
Seed
—
General Catalyst
—
Talent Signal
Hiring trend
● First snapshot
trend accrues with monthly sweeps
Open roles
7
via ashby
Product-build share
100%
engineering, research, product, design
Trajectory
steady
heavy product build — 100% of open roles are product-building functions (engineering/research/product) — 3 of 7 open roles are engineering.
Actively hiring with no tracked executive churn.
Open roles by month
Open roles by function
■ product-building ■ go-to-market / G&A
Research Scientist, AIStandard Cell Design LeadElectromechanical EngineerMechanical EngineerTechnical Program ManagerProcess Engineer
Counted from Substrate's live job board as of 2026-08-17; role functions classified from posting titles. Open-role counts are an activity signal, not headcount. Refreshed monthly.
Founders & Key People
James ProudOliver Proud
Investors
Founders Fund · General Catalyst · In-Q-Tel · Valor Equity Partners · Allen & Co. · Long Journey Ventures
Products
Soft/advanced X-ray lithography tool driven by a compact particle accelerator (sub-EUV alternative)
Planned vertically integrated US foundry running its own lithography tools
Private-company numbers are not real-time. Reflects publicly disclosed valuations from press releases, news reports, and tender offers as of 2025-Q4. Refreshed quarterly.