Samsung Electronics' HBM4E / Courtesy of Samsung ElectronicsSamsung Electronics' sales of sixth-generation high bandwidth memory chips, known as HBM4, surpassed $1 billion, industry sources said Tuesday.The milestone comes just four months after the South Korean tech giant became the first company in the world to begin mass production and shipments of HBM4 chips in February.Industry sources expect Samsung's HBM4 revenue to exceed $1.2 billion by the end of June.Samsung has rapidly expanded HBM4 shipments since the product's launch, helping it gain market share in the fast-growing HBM segment.HBM4 chips are designed for next-generation artificial intelligence (AI) accelerators, including Nvidia Corp.'s Vera Rubin platform. Nvidia's graphics processing units are widely used in generative AI applications.The global HBM market is currently dominated by fifth-generation HBM3E products. However, industry observers expect HBM4 to become a key growth driver as demand for advanced AI chips accelerates.