The distant geopolitical conflict in the Middle East is sending shock waves through Asia’s semiconductor industry, exposing fresh vulnerabilities in the supply chain as shortages of photoresist – a critical chipmaking material – emerge as the latest weak link.

With the Strait of Hormuz effectively closed since early March, supplies of naphtha – a key feedstock for specialty chemicals used in semiconductor production including photoresist – have been sharply curtailed.

Produced during the refining of crude oil or natural gas, naphtha is essential to the manufacture of advanced chips used in applications ranging from artificial intelligence to car systems.

South Korea’s memory chip giants Samsung Electronics and SK Hynix are among those most exposed.

Major Japanese photoresist suppliers had warned both firms of looming disruptions to raw material procurement, according to South Korean media outlet TheElec. The companies did not immediately respond to requests for comment on Thursday.

The shortage is expected to hit advanced nodes that rely on extreme ultraviolet (EUV) lithography the hardest, given the process’s sensitivity and tight tolerances.