(Image credit: Intel)
An Intel patent application published on July 2, 2026, has revealed the company's plans for a new high-bandwidth memory (HBM) architecture that aims to ease the packaging and cost bottleneck of today's interposer-based HBM. The patent application — filed back on December 26, 2024 — describes what Intel calls cross-batch memory (XBM), an "ultra-high-bandwidth memory with backend transistors" built with the goal of matching HBM4's footprint while swapping conventional DRAM and its ultra-wide interface for back-end-of-line (BEOL) transistors and serial Universal Chiplet Interconnect Express (UCIe) links.Intel's proposed design is a memory stack that addresses the assembly costs that make conventional HBM expensive by dropping the costly silicon interposer and shrinking the package, while building in its own defect repair.
Package cross-section showing the HBM stack (104) and logic die (106) on an interposer. (Image credit: Intel)The filing lays out a stack of memory dies, each holding one-transistor one-capacitor (1T1C) DRAM fabricated in the back-end-of-line, wired together with through-silicon via (TSV) "gutters" and both-sided high-bandwidth interconnect (HBI) connections. Intel describes dies of roughly 1.5 gigabytes (GB) apiece — 768 "datablocks" arranged in a 32-by-24 grid, grouped into eight channels of eight sub-channels each — stacked eight high and scaling to 16. Data then leaves the stack over UCIe I/O bundles running at 32 gigatransfers per second (GT/s), funneled out through a base die.To understand what Intel is changing, it helps to recall what standard high-bandwidth memory does. HBM stacks DRAM dies vertically on a base logic die, threads them together with TSVs, and communicates with the processor across a silicon interposer using an extremely wide parallel interface — on the order of 1,024 bits per stack. This width is how HBM delivers its bandwidth, but it is also what makes it expensive to package and hard to scale, as every one of those wires has to be routed through an interposer sitting between the memory and the compute die. As AI accelerators have outrun the rate at which memory can feed them, this "memory wall" has become the dominant constraint on performance, which is why nearly every large chipmaker is now attacking the interface and the stack rather than the logic.XBM's first major change is structural. Conventional DRAM cells are built in the front-end-of-line, the base silicon layer where transistors are normally fabricated. XBM instead moves the 1T1C cell into the back-end-of-line, the metal-and-via stack above the transistor layer, using thin-film transistors. Building memory in the BEOL is what lets Intel pack the die into many small, independently addressable memory blocks, and it is the same backend-transistor direction Intel has pursued for placing memory directly over logic.
