Lam Research is one of the world's largest makers of wafer-fabrication equipment, specializing in the etch, deposition and clean tools that carve, layer and strip the structures inside every chip. It is especially critical to 3D NAND and DRAM memory, and increasingly to advanced logic (gate-all-around) and packaging. Sitting one step upstream of the fabs, it sells to TSMC, Samsung, Intel, Micron and SK Hynix, and its fortunes ride the wafer-fab-equipment capex cycle, the memory upturn and the AI/HBM build-out.
Lam sits one step above the fabs
Lam doesn't make chips — it makes the etch, deposition and clean machines that fabs install to make them. It buys precision components and gases and sells finished tools to Micron, SK Hynix, Samsung, TSMC and Intel. ASML (litho) and KLA (process control) are complementary; Applied Materials and Tokyo Electron are the etch/deposition rivals.