YouTuber's backyard fab ambitions expand from RAM to homebrew LEDs

Dr. Semiconductor, also known as Dr. Matthew Hartensveld, a semiconductor engineer, has expanded his backyard fabrication ambitions beyond DRAM to manufacturing working LEDs in his backyard fab. After successfully building a class-100 cleanroom in his shed, Hartensveld moved on to constructing DRAM cells, which are essential components for DDR5 chips.

However, these cells still require significant fabrication and packaging work to become functional RAM chips. To address this challenge, Hartensveld turned to GaN (gallium nitride) LEDs, which are transparent and suitable for testing packaging processes. GaN LEDs are easier to attach to circuit boards due to their transparency, making them an ideal test bed for home packaging experimentation.

Hartensveld used a laser etcher with a 355 nm ultraviolet wavelength to etch GaN into LEDs, avoiding the use of hazardous chlorine gases and expensive equipment. After testing and confirming the success of the laser etching process, Hartensveld proceeded with traditional LED production, adding p-type and n-type contacts to create diodes.

He then bonded the LED to an ENIG-finished circuit board using indium bumps, demonstrating the process with a visible bond formation and power supply. The LEDs emitted blue light initially but could be modified to produce warmer white light using Cerium-doped yttrium aluminum garnet coating. Hartensveld's project not only democratizes LED manufacturing but also lays the groundwork for future work on shrinking transistors and capacitors, enabling the creation of more modern commercial DRAM modules.

The YouTuber plans to release open-source documentation for his entire process, including bills of materials and instructions for the cleanroom shed and the LED project.