DIY Semiconductor Enthusiast Creates Blue LEDs from Sapphire Wafers in Backyard Lab

Backyard Semiconductor Fabrication

Matthew Hartensveld, operating under the moniker Dr. Semiconductor, has expanded his backyard semiconductor cleanroom efforts by successfully creating blue LEDs. This follows his previous work on manufacturing RAM cells, all within a non-industrial environment. His projects are documented as part of the open-source Semiconductor.DIY initiative.

Etching with a Consumer Laser

Hartensveld began with gallium nitride on sapphire wafers. To define contact patterns, he used a powerful laser purchased from eBay, as industrial chlorine gas etching was not feasible. After experimentation, he managed to etch patterns onto the wafers, which is a critical step in semiconductor manufacturing.

LED Assembly and Testing

Following the etching, Hartensveld applied indium to a wafer shard and connected it to a 9V battery, successfully producing blue light, confirming the creation of a functional LED. He then cleaned the metallic gallium residue and used a vacuum chamber to deposit nickel/silver for the positive contact and titanium/silver for the N-contact and top metal, utilizing argon plasma.

Challenges in Packaging

The completed blue LED remained on the wafer. The next challenge involved packaging, which requires cutting the LEDs from the wafer and adding physical connections. Initial attempts with a table saw proved unsuccessful, indicating further development is needed for this stage of the process.