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YOU CAN MAKE A REAL LED CHIP AND LIGHT IT WITH A 9V BATTERY

You buy the hard part — the grown crystal — then turn it into working LED chips with a laser, hot caustic etch, and indium solder.

by Matthew Hartensveld, PhD

FULL CAD BOM FIRMWARE DOCS

WorkshopScience

difficulty
●●●●●
time
a weekend-plus for the shortcut, a month for the full process
license
CC BY-SA
repo
repo 0 stars

WHAT YOU’LL NEED

Videos
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COMPAREE VERDICT

This is semiconductor fabrication in a home workshop, and the guide is honest about what that means. You are not growing the gallium nitride crystal — that is the expensive part you buy as an epiwafer, a mirror-shiny sapphire disc that already contains the quantum wells where light is made. PM Optics sells red, green or blue LED epiwafers from about 160 dollars per 2-inch wafer, and one wafer diced into millimetre-scale chips is a lifetime supply for one person. The shortcut route gets you first light the same evening: laser-etch trenches down into the n-GaN layer, press on two pieces of indium, connect a 9V battery, and the chip glows blue. Add 25-micrometre Ce:YAG phosphor powder and it turns white. The full process adds bilayer lithography, sputtered contacts, and flip-chip bonding onto an ENIG board at 220 degrees. The one thing most likely to go wrong is the laser. This uses a Class 4 UV laser at 355 nm with an invisible beam that causes instant permanent eye damage, and the guide is not exaggerating when it says rated goggles and an enclosed working area are non-negotiable. The KOH etch is hot and caustic. China required export licences for gallium materials in 2023, so epiwafer lead times stretch. This is a serious fabrication project for someone who already knows their way around cleanroom chemistry and has real UV laser discipline. If that describes you, the guide is excellent and the payoff is real: a chip you made lighting up in your hand.

GOOD TO KNOW

  • —Full written guide published under CC BY-SA at semiconductor.diy/guides/making-leds.
  • —BOM is descriptive — PM Optics epiwafers start around 160 dollars per 2-inch wafer, 355 nm laser marker, KOH, LOR 5A and AZ1512 resists, nickel and silver sputter targets, indium, ENIG-finish PCB.
  • —No Gerbers, no firmware, no GitHub repository — this is a chemistry and optics guide, not a hardware build.
  • —A companion lithography guide is announced but not published yet.
  • —The guide states the licence plainly and there is no commercial restriction.
  • —Video version: 'Making LEDs at Home' on the Dr.Semiconductor channel, published 21 August 2026.

Parts to buy

8 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • InGaN LED epiwaferFind
  • 355 nm laser marking machineFind
  • KOHFind
  • LOR 5A and AZ1512 photoresistsFind
  • Nickel and silver sputter targetsFind
  • IndiumFind
  • ENIG-finish PCBFind
  • Ce:YAG phosphor powder (optional, for white light)Find

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Can I build this?

Printnothing required
BuyInGaN LED epiwafer (red, green or blue, PM Optics or UniversityWafer, around 160 dollars per 2-inch wafer), 355 nm laser marking machine, KOH, LOR 5A and AZ1512 photoresists, nickel and silver sputter targets, indium, ENIG-finish PCB, Ce:YAG phosphor powder (optional, for white light)
Tools355 nm UV laser marker (Class 4), sputter coater or vacuum chamber for contact deposition, spin coater for lithography, hotplate, rated 355 nm laser goggles, enclosed laser work area, chemical fume hood or ventilation for KOH
Skillscleanroom lithography experience, vacuum deposition, laser safety discipline, caustic chemical handling — this is not a first semiconductor project
Timean evening for the shortcut (laser trenches plus indium plus 9V test); the full process takes several sessions with an hour-long KOH step, two lithography and sputter rounds, overnight lift-offs, dicing and packaging, if you already have the vacuum and lithography tools
Cost$$$, dominated by the epiwafer (160 dollars per 2-inch wafer) and the 355 nm laser marker if you do not already have one
SafetyClass 4 UV laser at 355 nm with an invisible beam causing instant eye damage — rated goggles and an enclosed working area are non-negotiable. Hot caustic KOH, TMAH developer (toxic on skin contact, wear gloves), hot solvents and metal fumes from the anneal. Read the SDS for anything you have not used before.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

Making LEDs at Home

The video version of the guide on the Dr.Semiconductor channel, covering the shortcut and the full process.

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Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the full guide at semiconductor.diy/guides/making-leds and decide if you have the UV laser discipline and cleanroom chemistry experience for this. (The guide states the safety requirements plainly — if you do not already have a Class 4 laser enclosure and rated 355 nm goggles, build those first.)
  2. 2.Source an InGaN LED epiwafer — PM Optics, UniversityWafer, PAM-XIAMEN Powerway or Ganwafer, noting that gallium export licences stretch lead times.(Red, green or blue, 2-inch wafer runs about 160 dollars and is a lifetime supply diced into millimetre-scale chips.)
  3. 3.Start with the shortcut: laser-etch trenches, press indium, connect a 9V battery through a resistor of a few hundred ohms and verify first light before committing to the full lithography process.(If the shortcut does not work, the full process will not either — this verifies the epiwafer and your laser parameters.)

KNOWN ISSUES

  • Buying a 355 nm laser marker without understanding that it is a Class 4 device with an invisible beam that causes instant permanent eye damage — the guide is not overstating this, and rated goggles plus an enclosed area are mandatory before you power it on.
  • Assuming the epiwafer ships fast — China has required export licences for gallium materials since 2023, so lead times from China-based suppliers can stretch; order before you need it.
  • Skipping the shortcut route and going straight to full lithography, then discovering your laser parameters are wrong or the epiwafer is defective after a weekend of bilayer resist work.
  • Not setting up ventilation and protection for the wet chemistry: hot KOH, TMAH developer, hot solvents (acetone, IPA, DMSO) and metal fumes from the 450 °C anneal all need gloves and a ventilated workspace.
  • Expecting the companion lithography guide to be published — it is announced but not live yet, so if you do not already know bilayer resist processes, you will be learning from other sources.
  • Treating the full process as a beginner project — the shortcut is beginner-friendly, but the full process needs lithography, a sputter system with good vacuum, and safe handling of TMAH, solvents and hot KOH.

Can I grow the gallium nitride crystal at home?

No. The guide is explicit: the hardest part of an LED, the crystal growth, is the part you buy. An InGaN epiwafer is a single-crystal film already containing n-GaN, quantum wells and p-GaN grown on sapphire by MOCVD, and that process requires equipment and precursors far beyond a home workshop. The epiwafer is the expensive part, and everything else in the guide is turning that bought wafer into packaged chips.

How many LEDs does one 2-inch wafer make?

The guide calls a 2-inch wafer diced into millimetre-scale chips a lifetime supply for one person. The exact count depends on your die size, the 30-50 micrometre laser kerf and your yield, but it is in the hundreds to low thousands.

What is the difference between the shortcut and the full process?

The shortcut skips lithography and proper contacts: you laser-etch trenches down into the n-GaN, press two pieces of indium onto the p and n regions, and touch a 9V battery across them with a resistor of a few hundred ohms in series to get first light the same evening. The full process adds KOH damage recovery, bilayer lithography with LOR 5A and AZ1512, sputtered and air-annealed Ni/Ag p-contacts, a Ti/Ag top metal, laser dicing, and indium flip-chip bonding onto an ENIG-finish PCB at 220 degrees for a packaged device.

Do I need a cleanroom?

The guide does not require a rated cleanroom, but it does require cleanroom discipline — dust and fingerprints ruin lithography, and the KOH etch needs ventilation. If you have done photolithography before, you know the setup; if you have not, this is not the project to learn on.

Can I use a different laser?

The guide specifies a 355 nm UV laser marking machine because that wavelength is absorbed by GaN and allows precise trench etching. A visible-wavelength laser will not work, and a higher-power UV source without marking control will destroy the wafer. The guide describes the laser as a chainsaw and the KOH as sandpaper — you need both, and the laser has to be 355 nm.

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Discussion1

FROM THE COMPAREE TEAM

The guide says one 2-inch epiwafer diced into millimetre-scale chips is a lifetime supply of LEDs for one person. What would you actually build with that many chips?

CompareeTEAM1mo agoedited

Practical notes from our verification: the written guide on semiconductor.diy is live and detailed, but the companion lithography guide is marked as coming soon, so if you do not already know bilayer resist processes you will be learning from other sources. The video version, 'Making LEDs at Home', is on the creator's Dr.Semiconductor YouTube channel, linked from the site. There is no public code or file repository; the guide itself is the source, published under CC BY-SA. The single biggest safety note is not negotiable: this uses a Class 4 UV laser with an invisible 355 nm beam that causes instant eye damage, and the guide is right that rated goggles and an enclosed working area are mandatory before you power it on. The shortcut route — laser trenches, indium, 9V battery — is the right place to start, because if that does not light up, the full lithography process will not either. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

Matthew Hartensveld, PhD

Dr. Matthew Hartensveld is a semiconductor engineer who publishes as Dr.Semiconductor and fabricates chips in a cleanroom he built in a backyard shed. His guide runs from a beginner shortcut that lights up with a 9V battery to a full lithography and packaging process. Its core insight: the hardest part of an LED, the crystal growth, is the part you can buy.

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