Gallium nitride, as a core wide‑bandgap semiconductor material, has seen rapid capacity expansion for power devices and RF chips throughout 2026. Unlike monocrystalline silicon wafers, GaN substrates reach Mohs hardness between 8.5‑9.0, featuring stable chemical bonding energy, which brings special difficulties to conventional chemical‑mechanical planarization processes. Ordinary general‑purpose polyurethane CMP pads for silicon cannot meet GaN processing requirements, and material matching has become one of the main bottlenecks restricting mass‑production yield.
In actual fab operation feedback, improperly matched pad formulas easily cause two typical defects: insufficient material removal rate leading to low throughput, or excessive mechanical abrasion introducing micro‑scratches and subsurface damage on GaN wafer surfaces. For epitaxial‑grown GaN‑on‑Si and GaN‑on‑SiC structures, even tiny surface scratches will directly deteriorate the electrical performance of subsequent devices. Industry test data shows qualified GaN‑dedicated polyurethane pads need to balance pore structure, hardness and chemical resistance simultaneously. Pore size is commonly controlled within 25 μm‑50 μm to realize stable slurry holding and effective residue discharge, avoiding pore clogging during long‑time continuous polishing.
Many semiconductor consumable developers are now adjusting cross‑linking systems of thermoset polyurethane for GaN scenarios. Hardness design must strike a fine balance: overly hard pads produce scratches, while excessively soft pads sacrifice global planarization capability across the whole wafer. Multi‑layer composite structures combining rigid top polishing layer and compliant sub‑pad have gradually become mainstream solutions for GaN CMP processing.
Drawing from our accumulated experience in high‑performance polyurethane material development, we optimize base polymer formulation and micro‑foaming parameters targeting GaN polishing characteristics. Our material solution focuses on stable pore consistency, good resistance to alkaline and acidic CMP slurry, and low particle‑shedding performance. It supports fabs to obtain atom‑level smooth GaN surfaces while maintaining acceptable removal efficiency, helping clients shorten process debugging cycles for compound‑semiconductor mass production.