Micron plans foundry-process base dies for HBM4E and NVHBM

Micron said on September 30, 2026, that its HBM4E and custom NVHBM products would use base dies made on foundry processes. The plan marks a change from Micron’s HBM4 approach, which pairs DRAM core dies with an in-house base die. Samsung, meanwhile, is reportedly considering two foundry options for custom HBM, with the choice depending on customer needs.

Micron puts HBM4E and NVHBM on a foundry-process path

At Micron’s fiscal 2026 fourth-quarter earnings event, Chief Technology and Products Officer Scott DeBoer said the company’s JEDEC-standard HBM4E family and custom NVHBM, co-designed with NVIDIA, were being developed with foundry-process base dies.

Micron’s HBM4 approach pairs 1β DRAM core dies with an in-house base die. HBM4E’s move to foundry-process base dies changes how that layer is made; DeBoer’s statement covered both HBM4E and NVHBM.

Why NVHBM gives the base die a bigger role

An HBM base die sits beneath the stacked DRAM dies, connects the memory stack to the host processor and can carry control and interface logic. NVIDIA announced NVHBM in August 2026 with its custom memory controller integrated into that base die rather than the XPU die.

NVIDIA says NVHBM can deliver up to 30% more memory bandwidth, reduce HBM power consumption by 15% and free up to 25% more area on the XPU compute die compared with standard HBM4E. Those are NVIDIA’s stated comparisons. The controller’s placement helps explain why base-die design and fabrication feature prominently in the custom-memory architecture.

Samsung’s reported options depend on customer needs

Samsung Electronics is reportedly considering either Samsung Foundry or TSMC to make base dies for custom HBM, depending on customer requirements. Samsung Memory is also reported to support design and optimization when a TSMC-made base die is used. A customer is reportedly designing a product that pairs Samsung HBM core dies with a TSMC-process base die.

The reported approach ties the foundry choice, product selection and volumes to demand. It describes a customer-dependent option, rather than a single supplier route for all of Samsung’s custom HBM.

Two different sourcing scopes

Micron’s stated foundry-process plan covers both JEDEC-standard HBM4E and custom NVHBM. Samsung’s reported options concern custom-HBM base dies and vary with customer requirements. In both cases, the base die is the layer connecting the stacked memory to the host; in NVHBM, it also houses NVIDIA’s custom memory controller.