Tokyo Ohka Kogyo Co., JSR Corp. and Shin-Etsu Chemical Co.: Three seemingly inconspicuous companies suddenly came into the spotlight in early July when Japan announced it would slap tightened export controls to South Korea on three key chemicals — photoresists, fluorinated polyimide and hydrogen fluoride — that could be diverted for manufacturing weapons.
Behind the development of cutting-edge, palm-sized smartphones that dwarf the capabilities of 1980s desktop computers lies an advanced type of liquid that responds to beams of light to coat and etch finely detailed patterns on semiconductor circuit boards using a technique called photolithography — a process that uses one of the three chemicals.
TOK, JSR Corp. and Shin-Etsu Chemical control roughly 90 percent of the extreme ultraviolet (EUV) photoresists market, which are used for cutting-edge 7 nanometer chips.