Micron Technology has sued Chinese memory maker Yangtze Memory Technologies, or YMTC, accusing it of systematically poaching Micron engineers to obtain 3D NAND trade secrets and then using those engineers' patents to sue Micron. The 103-page complaint, filed September 15 in federal court in Idaho, escalates a patent war that has already spread across three continents.
Micron alleges YMTC targeted its Idaho workforce, naming former process engineer Hongbin Zhu as a defendant alongside the company. Zhu worked at Micron's Boise campus from January 2006 to September 2017, according to the complaint, and five employees left Micron in mid-2017, three of them from Boise, citing family or personal reasons. Several did not update their LinkedIn profiles to show their new jobs at YMTC. As of July 2026, Zhu's profile still listed him as a Micron engineer, Micron says.
The complaint goes beyond the familiar claim that departing employees carried manufacturing know-how with them. Micron alleges YMTC used the information to develop its 64-layer, 128-layer, and 232-layer NAND chips and, crucially, incorporated it into a patent portfolio. Micron says it discovered the scheme while defending itself: YMTC began suing Micron for patent infringement in California in November 2023, and several of the patents asserted against it named former Micron engineers as inventors. Micron is asking the court to transfer ownership of four YMTC patents, including US '851, back to Micron, and brings claims under federal and Idaho trade secret laws plus breach of contract against Zhu.
YMTC's campaign, meanwhile, has already scored. On September 18, the Munich Regional Court ruled in the first instance that Micron had infringed two German utility models held by YMTC, barring the affected products from sale in Germany, in two of five cases YMTC filed there. Micron rejected the claims and has appealed. The German suits sit alongside litigation in Texas, the United Kingdom, and China.
For enterprise IT, the case is a reminder that the memory supply chain is now a courtroom as much as a fab. Patent enforcement campaigns can restrict product availability in entire jurisdictions, and the dispute underscores how tightly memory technology, talent flows, and geopolitics are intertwined. Whatever the courts decide, expect the memory industry's legal battles to keep running in parallel with its technology roadmap.